Malicious PDF — malware analysis report

Static analysis result for SHA-256 91620f7d0f541d4e…

MALICIOUS

PDF

72.0 KB Created: 2021-02-05 19:45:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: f7fc18dcce6e33ed244a8a430839f2e0 SHA-1: ab5e51307e03323606a5fd6a2b80db7dc3b560c3 SHA-256: 91620f7d0f541d4eeddd694cb7048c2d4b4e630c2294b5b6359305718365c27d
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links pointing to various domains, many of which appear to be disposable hosting. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute further malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and an ML classifier also flagged it with high confidence. The embedded URLs and the heuristic firings strongly suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bologen.ru/wb?keyword=3%20hours%2024%20minutes%20in%20decimal%20form PDF link annotation
    • https://pufukowog.weebly.com/uploads/1/3/4/5/134583281/52603ad0d724.pdfIn PDF document text
    • http://vizionsmc.net/super_car_racing_multiplayer_hackje15p.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488560/normal_5fc687e67be3b.pdfIn PDF document text
    • https://cdn.sqhk.co/foroboreb/gcbbghg/captions_for_maternity_photoshoot.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417405/normal_6001d8dc585b5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491451/normal_5fd1494385ae7.pdfIn PDF document text
    • http://haifaiv.ru/joxiruluwiksqpl0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366015/normal_601c5fcf8968a.pdfIn PDF document text
    • https://karujelibofab.weebly.com/uploads/1/3/1/4/131406149/4008449.pdfIn PDF document text
    • http://legendnat.space/litavelofirajunolefataxpd1up.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487206/normal_600f969dbc307.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406820/normal_6014ff4fb4b78.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/vojapu/show_similar_to_girlfriends_guide_to_divorce.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ccb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB7 5432 bytes
SHA-256: bc08f127508f293dc63ac1daa4453833d7167de81cf73450daf161b1d20e8027
font_01_sfnt_off0000df03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF03 11124 bytes
SHA-256: 1346447393d2bd9288b4e96760fdff5d5a3153b305706ea8cb58c1397d1d963b
font_02_sfnt_off000104f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F6 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378

Open this report in the interactive analyzer, or submit your own file for analysis.