Malicious PDF — malware analysis report

Static analysis result for SHA-256 a77d1e57d78e0585…

MALICIOUS

PDF

77.1 KB Created: 2021-05-19 21:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 54024671e49cab5d8f461a5150850e15 SHA-1: 29453cd94b781c34121984705d09cf13730a6683 SHA-256: a77d1e57d78e05853f756c7401027e95a321a00c406bbef407af52cb01a72ded
186 Risk Score

Malware Insights

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

This PDF document was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs, with a primary suspicious URL being https://zajinet.ru/strik?utm_term=spanish+lab+answers. The document's structure and embedded links suggest an attempt to lure users to potentially malicious websites, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://zajinet.ru/strik?utm_term=spanish+lab+answers PDF link annotation
    • https://goluluvofa.weebly.com/uploads/1/3/2/7/132712214/durukasiderumika.pdfIn PDF document text
    • https://fosozofafeg.weebly.com/uploads/1/3/1/8/131856121/8151235.pdfIn PDF document text
    • https://bogilerilixami.weebly.com/uploads/1/3/5/3/135345361/kakubetaxomi_jiluvoweli_femifes.pdfIn PDF document text
    • https://rikizanasurixa.weebly.com/uploads/1/3/1/3/131379420/lodutof.pdfIn PDF document text
    • https://famosufed.weebly.com/uploads/1/3/4/9/134900490/90cd2908d.pdfIn PDF document text
    • https://pidofuvu.weebly.com/uploads/1/3/0/7/130739764/102c2e98970c49.pdfIn PDF document text
    • https://vekerarefatada.weebly.com/uploads/1/3/4/8/134868636/relatebotiz.pdfIn PDF document text
    • https://zogabugopevaluz.weebly.com/uploads/1/3/0/8/130814784/38fce6e66b9bc8b.pdfIn PDF document text
    • https://mudabomem.weebly.com/uploads/1/3/0/9/130969182/tigiju.pdfIn PDF document text
    • https://wobafelu.weebly.com/uploads/1/3/4/6/134613510/ef6377c0bbd.pdfIn PDF document text
    • https://depopuxa.weebly.com/uploads/1/3/4/8/134893869/1162484.pdfIn PDF document text
    • https://pinuzika.weebly.com/uploads/1/3/4/6/134640149/regasuvone.pdfIn PDF document text
    • https://wajovojov.weebly.com/uploads/1/3/4/6/134652085/665f3.pdfIn PDF document text
    • https://fovivijidilel.weebly.com/uploads/1/3/4/8/134888041/133e4de.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ee28299-8384-4aaa-b875-b10ad8b005ab/50008055959.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0cdd1ec-6f12-4524-9a46-61745f4cb4a2/math_worksheet_for_kindergarten_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6b62707-c773-487f-bf91-57e63306ef8d/66484469391.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/76ce75a4-5fa1-4b23-9c96-d75e26ecdc6a/51023480361.pdfIn PDF document text
    • https://s3.amazonaws.com/votubukaxogilix/larafawefutusawiwupuder.pdfIn PDF document text
    • https://s3.amazonaws.com/dobikasukavu/latest_bluetooth_for_windows_7.pdfIn PDF document text
    • https://s3.amazonaws.com/wizuluworafid/forex_for_beginners_book_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05cafb63-a5de-4923-a7a4-c1214ffda759/8228125447.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8820ea98-dec6-4785-8eb2-c43d062f0fe6/does_the_bible_have_contradictions_quora.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_off0000eeb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB5 5244 bytes
SHA-256: fb55ee6977bbe0e53ef5217370be80b813f411c030cd9f53421e3fe18daec446
font_01_sfnt_off0001008c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008C 10812 bytes
SHA-256: 2ce379097990278c805b5a3a2585fdb25df188ac286868d62142a266c61aa8df