Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a3f7974eb738f0d…

MALICIOUS

PDF

44.9 KB Created: 2020-08-29 07:13:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d3f67614c945a2d1f127d79989612096 SHA-1: d1740acd1ed3e3037f80b1a9a7dcb0b00925c852 SHA-256: 9a3f7974eb738f0d71a60cbf4390e069c3589246fcfc8a4c33be838fb13009e3
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL that triggered this finding. The presence of numerous other PDF links, many pointing to benign content, suggests a link farm or SEO poisoning technique to mask the malicious redirector.

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.ru/wix?keyword=can+moment+of+inertia+be+negative
    • https://static.usrfiles.com/ugd/b8c837_4d449b3996d6457399ee79d7ab0a118c.pdf
    • https://static.usrfiles.com/ugd/b8c837_847181db77ea4b77923e3445bc95c134.pdf
    • https://static.usrfiles.com/ugd/b8c837_dc34892d73aa410796328ad677a3cb17.pdf
    • https://cdn.shopify.com/s/files/1/0428/5143/4659/files/jukuxaluliwujon.pdf
    • https://cdn.shopify.com/s/files/1/0437/7480/4126/files/wilizajosaxodezi.pdf
    • https://cdn.shopify.com/s/files/1/0438/1153/7053/files/xafozozapisiwanaguf.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/boguxexu.pdf
    • https://cdn.shopify.com/s/files/1/0432/3350/9534/files/mazanedemoluvolereni.pdf
    • https://static.usrfiles.com/ugd/b8c837_3a0e5c92cab94dbdab4a6c36a4127354.pdf
    • https://static.usrfiles.com/ugd/b8c837_f07c65a23bd341119e646d37fcfb6133.pdf
    • https://static.usrfiles.com/ugd/b8c837_060138f2871a49a7bc2d626374364a97.pdf
    • https://static.usrfiles.com/ugd/b8c837_126fc4e8036b4a018433c4911e9352bf.pdf
    • https://static.usrfiles.com/ugd/b8c837_43aae4f008354d968d8e0335d3f93909.pdf
    • https://static.usrfiles.com/ugd/b8c837_5c0101b12be4433f90a782b02d807459.pdf
    • https://static.usrfiles.com/ugd/b8c837_17db77abc1ae44e0948b522787e92986.pdf
    • https://static.usrfiles.com/ugd/b8c837_1fdf14fbccdf47169eb3b1d1f1c95a63.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_off0000727f.bin
4d5ab5435168e8eadbf0622600e99d9e445c3c343420aa1d099776dbe6df3a9d
pdf-font-stream PDF embedded font (sfnt) at offset 0x727F 4984 bytes
font_01_sfnt_off0000836e.bin
514aca812f07c653d3ff8ff12741bbf8fb62871799107a301fbe5496add11a97
pdf-font-stream PDF embedded font (sfnt) at offset 0x836E 10352 bytes