Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a27df2cfbd0608…

MALICIOUS

PDF

102.3 KB Created: 2021-05-07 02:25:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 8ecc269d64bbd2bdb97aef5be4b0ac66 SHA-1: 20ece923cc91874adf56e0e2ff261648b74de6a3 SHA-256: 81a27df2cfbd06088a73f4a283bc8be8f1c1cdb2a01cbe59bb363d245a0fa8ae
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicative of a link farm or phishing operation. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and numerous external URLs suggest it's designed to redirect users to potentially malicious content, likely as part of a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jottigo.ru/strik?utm_term=1996+ford+ranger+problems PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4408336/normal_5fe6931f9bd2f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393016/normal_5fe273c9f22d9.pdfIn PDF document text
    • http://magazinrf.xyz/how_to_hook_up_n64_with_rfu_adapter399ur.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458431/normal_5ff8a875988f5.pdfIn PDF document text
    • http://fakts.design/7517939622w54wj.pdfIn PDF document text
    • https://sinuvofibudibaf.weebly.com/uploads/1/3/2/6/132696377/4130369.pdfIn PDF document text
    • https://vifewilepame.weebly.com/uploads/1/3/4/0/134012930/1349717.pdfIn PDF document text
    • http://bella24.xyz/what_is_medical_microbiology_laboratoryplrbi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496015/normal_602cf497a4250.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4444110/normal_5feeb73b8f2b3.pdfIn PDF document text
    • https://loxoxonejuk.weebly.com/uploads/1/3/4/6/134684666/352731.pdfIn PDF document text
    • https://tubolapibakosi.weebly.com/uploads/1/3/4/8/134872187/52100ebf2b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490934/normal_5fc65ccb2fb4b.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://01c19f78-c7d0-441a-b56a-8672493f87de.filesusr.com/ugd/9d66c7_900ebcd424164e4eae249b80da8c5bca.pdf?index=trueIn PDF document text
    • https://40e214c1-1950-44e8-a195-e2c6eeb23253.filesusr.com/ugd/a517f4_6aad5f533eb14839afca7d924f5feaaa.pdf?index=trueIn PDF document text
    • https://e29f0852-aa8c-4fc4-a5db-fcd144ab7086.filesusr.com/ugd/b730be_a1bcecf75c7f4c14978317b2f616ba70.pdf?index=trueIn PDF document text
    • https://bb74f61c-7045-47bf-9a7e-968101ee373e.filesusr.com/ugd/81ef4b_ea38cfe349fa4650b101edfae98143cb.pdf?index=trueIn PDF document text
    • https://75edee45-cd08-43cb-a752-0c33e5c2343f.filesusr.com/ugd/a7c173_5dfa4cb5e05c4ca6b9c651c0e860855d.pdf?index=trueIn 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_off000145ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145AD 5428 bytes
SHA-256: 68791708238d90af33d88902977c48253bce2d7e014fbe457f3a4d9cd5b7a741
font_01_sfnt_off000157f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157F4 11236 bytes
SHA-256: 2fa0dede16a2f289516d121475dbdf5a4e7fd9f5277b96cea5b4ed140c19e67a
font_02_sfnt_off00017de8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17DE8 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2