Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c287e067b014e80…

MALICIOUS

PDF

42.7 KB Created: 2020-09-04 11:14:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1d878a78a0e4f5d134e766a8850edbe2 SHA-1: 5b26d816b7e4de5da76d434a1943739a0c5d73d7 SHA-256: 9c287e067b014e80d8caeb509e20d4edcc3b55d741b481fe382e56179d827f09
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.me/wix?keyword=writing+half+reactions+practice+worksheet+answers'. This URL is embedded within the document body, disguised as a link to worksheet answers. The ML classifier also strongly flagged this PDF as malicious. The document appears to be a link farm, with numerous embedded URLs, many hosted on static.usrfiles.com, likely to improve search engine ranking and lure unsuspecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ttraff.me/wix?keyword=writing+half+reactions+practice+worksheet+answers
    • https://static.usrfiles.com/ugd/c3548c_cfbc03d64f9e42cb87b565a67b7115cd.pdf
    • https://static.usrfiles.com/ugd/b8c837_663a55f8981a44bc82b73d35778bb442.pdf
    • https://static.usrfiles.com/ugd/e5412a_cf840a01b95943709c70abe7ff6f6cd8.pdf
    • https://static.usrfiles.com/ugd/e643da_9d7f9a7a40ab45acae46326f65563b7d.pdf
    • https://static.usrfiles.com/ugd/10b11f_d5f6a3f6a0854c788cc4950e95401a88.pdf
    • https://static.usrfiles.com/ugd/87a178_5163d26106cc47a09fbbe306a4b1dbee.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/tokisesuzarutaxiwiru.pdf
    • https://cdn.shopify.com/s/files/1/0433/1952/5534/files/92343291203.pdf
    • https://cdn.shopify.com/s/files/1/0465/5012/2654/files/60231935434.pdf
    • https://cdn.shopify.com/s/files/1/0449/9403/5880/files/face_sheet_mask_boots.pdf
    • https://static.usrfiles.com/ugd/bb13a2_87bd7f4294114afda92113b6f3cb3ed4.pdf
    • https://static.usrfiles.com/ugd/01bc73_5678ef6f09084c7485e68a733e958d7b.pdf
    • https://static.usrfiles.com/ugd/440e29_594cba7919764e2a90497ba66fb29481.pdf
    • https://static.usrfiles.com/ugd/1849a1_830016abff7d46a7b4ae3420392ceeda.pdf
    • https://static.usrfiles.com/ugd/e2c6c1_c4ca92272b074b639ba88f5357b74123.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000066a1.bin
0852b8c55f5f1e0bebf29d91eb5e4290e80f489ebfb6a2234a6d3a35616fc6e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x66A1 5444 bytes
font_01_sfnt_off00007949.bin
9fbe8f2d8914ae7bbbb4bd94dc81c653785d23843592969c88d6e0cb86dc55d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x7949 10688 bytes