Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eb3621c8da1039f…

MALICIOUS

PDF

37.4 KB Created: 2020-09-04 08:05:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 103e6516019becf3a8b4e47e76c5c14e SHA-1: ae0dc19f0aff45fffcaaacbcc4ca7e95326da643 SHA-256: 4eb3621c8da1039f43b66a97ba09bc34922dd34c2a175b3315153e16f2c31ca1
152 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and contains a significant number of embedded links. The heuristic PDF_SEO_LINK_FARM indicates a link farm structure, likely for SEO manipulation. Crucially, the PDF_MALICIOUS_REDIRECTOR_LINK heuristic fired, pointing to a known malicious redirector URL. The document body itself is heavily obfuscated but contains the same malicious URL, suggesting the primary intent is to redirect users to malicious content.

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=simple+present+tense+review+exercises+pdf
    • https://static.usrfiles.com/ugd/338562_cd0ad57e7e5e4cea899e1c4e395ff6ee.pdf
    • https://static.usrfiles.com/ugd/eda9ba_9b1ab06fc2e34377a0eb226d7044e8be.pdf
    • https://static.usrfiles.com/ugd/c63dba_b31760483283475185b2d97096f40d8a.pdf
    • https://cdn.shopify.com/s/files/1/0439/4424/7451/files/caterpillar_416c_backhoe_service_manual.pdf
    • https://cdn.shopify.com/s/files/1/0435/4103/7208/files/bsnes_emulator_mac.pdf
    • https://cdn.shopify.com/s/files/1/0429/5933/9674/files/86715106578.pdf
    • https://cdn.shopify.com/s/files/1/0451/7930/6135/files/boost_juice_nutritional_information.pdf
    • https://cdn.shopify.com/s/files/1/0430/4309/4677/files/39009304192.pdf
    • https://cdn.shopify.com/s/files/1/0432/0431/3247/files/first_day_of_school_activities_1st_grade.pdf
    • https://cdn.shopify.com/s/files/1/0439/6885/6222/files/jtrent238_discord_bots.pdf
    • https://cdn.shopify.com/s/files/1/0430/1642/1529/files/servant_song_sheet_music.pdf
    • https://static.usrfiles.com/ugd/b972d5_88e5e12655e147dea897108340a67aab.pdf
    • https://static.usrfiles.com/ugd/bf650e_1a629dfeb7434a058a2ddd6ddcbd2741.pdf
    • https://static.usrfiles.com/ugd/40512e_27e9c9a8f0de40e2be7afedfffb3857c.pdf
    • https://static.usrfiles.com/ugd/7c3584_e5bad66c34ca48e682f745c2fe524996.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_off000053ec.bin
ad36c001927977033d6236de44b78d67fbb3ab4e58def73d6557ba0d4b06d990
pdf-font-stream PDF embedded font (sfnt) at offset 0x53EC 5412 bytes
font_01_sfnt_off0000665a.bin
58fd22ae4e0b557961815cdbe297610a20d51d002e8258803f0ea0c36d4e3736
pdf-font-stream PDF embedded font (sfnt) at offset 0x665A 10008 bytes