X0305 4 2012-06-19 0 0001010086 SIGA TECHNOLOGIES INC SIGA 0000918939 MacAndrews & Forbes Holdings Inc. 35 EAST 62ND STREET NEW YORK NY 10065 1 0 1 0 0001186472 PERELMAN RONALD O 35 EAST 62ND STREET NEW YORK NY 10065 1 0 1 0 0000740740 MacAndrews & Forbes LLC 35 EAST 62ND STREET NEW YORK NY 10065 1 0 1 0 Warrant (Right to Buy) 2.95 2012-06-19 4 J 0 247272 0.00 D 2008-06-19 2012-06-19 Common Stock 247272 0 I Owned through wholly-owned corporation Warrant (Right to Buy) 2.95 2012-06-19 4 J 0 247272 0.00 A 2008-06-19 2014-06-19 Common Stock 247272 247272 I Owned through wholly-owned corporation These warrants to purchase shares of the common stock ("Common Stock") of SIGA Technologies, Inc. ("SIGA") were acquired by MacAndrews & Forbes LLC on June 19, 2008 pursuant to a Letter Agreement, by and between SIGA and MacAndrews & Forbes LLC. These warrants were previously reported at the time of acquisition as the right to buy 238,000 shares of Common Stock at an exercise price of $3.06 per share, but, pursuant to the anti-dilution provisions of the warrants, were adjusted to reflect the effects of certain of SIGA's subsequent issuances. On June 19, 2012, the term of a Warrant Agreement with MacAndrews & Forbes LLC, covering 247,272 shares and initially issued in 2008, was extended to June 19, 2014. Ronald O. Perelman, a joint filer hereunder, beneficially owns 100% of the common stock of MacAndrews & Forbes Holdings Inc., which beneficially owns 100% of the equity interests of MacAndrews & Forbes LLC, a joint filer hereunder. MacAndrews & Forbes LLC beneficially owns the securities described above. /s/ Barry F. Schwartz, Executive Vice Chairman 2012-06-19 /s/ Barry F. Schwartz for Ronald O. Perelman pursuant to a Power of Attorney filed with the Securities and Exchange Commission 2012-06-19 /s/ Barry F. Schwartz, Executive Vice Chairman 2012-06-19