Malicious PDF — malware analysis report

Static analysis result for SHA-256 a22c6824e8097535…

MALICIOUS

PDF

72.6 KB Created: 2021-03-18 09:32:29 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 7d9877d600c7d1789aca26b494d93ea5 SHA-1: f144ec9b4b04b03c5f86e55d37d9462fd2fb06b6 SHA-256: a22c6824e80975353bf2e43054490416f3c40683c9c922d4afbe33129d71c05d
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body, though heavily obfuscated, appears to be a lure related to "3.4 assessment biology answers pg 87", aiming to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://dafemum.ru/wix?keyword=3.4+assessment+biology+answers+pg+87 PDF link annotation
    • https://cdn.sqhk.co/sopiloroda/bhegchb/8728968067.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372740/normal_603ea355aa36a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4383924/normal_5fc6776c119df.pdfIn PDF document text
    • https://cdn.sqhk.co/tokexinolelu/pggMZhb/cue_sheet_flac_teilen.pdfIn PDF document text
    • http://zugugalepew.mypressonline.com/sat_bad_score.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377925/normal_6007ffe15b5cd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417023/normal_5ff7caa3d84ad.pdfIn PDF document text
    • http://fulokixowo.scienceontheweb.net/blumer_1969_symbolic_interactionism.pdfIn PDF document text
    • https://cdn.sqhk.co/bapisolel/ifhjjhT/1887877918.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414166/normal_602cb1e7df9a5.pdfIn PDF document text
    • http://getepitisux.mywebcommunity.org/mastering_the_rockefeller_habits_verne_harnish.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f405dec1-7f90-4f4c-a861-5286f67d0127.filesusr.com/ugd/ab922d_12931e43347c4a578f6cf32c4bfc95ac.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mawesenasijoser/92229874698.pdfIn PDF document text
    • https://s3.amazonaws.com/nijosinizo/xuxabinumepab.pdfIn PDF document text
    • https://02bc4616-4eae-4b38-b2c9-0e654f754ee0.filesusr.com/ugd/069df5_6eece89b4c004cedbed01747326df579.pdf?index=trueIn PDF document text
    • https://d5bea983-5bca-41ba-aae6-6b688785cc77.filesusr.com/ugd/9ec29b_3d99ae4678b9499e925806dddee88d70.pdf?index=trueIn PDF document text
    • https://a179b4bb-f9e1-4b0b-8685-f881d2afde68.filesusr.com/ugd/0fdb6d_f2e0006a873a4a8db3cff6a555ab0d68.pdf?index=trueIn PDF document text
    • https://c06d174a-caca-4ab2-b5a0-4525cd3135d4.filesusr.com/ugd/856cea_113610551d4a40a88b4f426f67cf9fdc.pdf?index=trueIn PDF document text
    • https://6f81cef9-66a2-447d-9e1d-4c0427ef15c5.filesusr.com/ugd/4d935e_29bf215bd85f4e0c99c1a29ee7e09d27.pdf?index=trueIn PDF document text
    • https://36622f5a-5a1b-41a5-aa98-965156e47ac2.filesusr.com/ugd/804ff6_b9ac6ef326964352995f05e8dc376767.pdf?index=trueIn PDF document text
    • https://1c019786-7048-4615-837a-ae53f087c4ae.filesusr.com/ugd/8b4172_319658be14f74a46a325445db5acd378.pdf?index=trueIn PDF document text
    • http://roveramo.atwebpages.com/timeme.pdfIn PDF document text
    • http://doriponesarom.myartsonline.com/patixo.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000deb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB1 5936 bytes
SHA-256: cf5c2a9220b5e91db7f85f4994a8baa5e2ce2ebf7817125dfb40984da64c8ad2
font_01_sfnt_off0000f2f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F2 9852 bytes
SHA-256: cc2d3b605a95cf50c731e57d19cd2c842dd1d6cca375807083e4e9e799202d16