Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cc4c9d6b9d21c0a…

MALICIOUS

PDF

81.9 KB Created: 2021-03-31 04:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ccb1c91e7f6733f2a6d403a54f34885b SHA-1: 2ef38b0b6cae5cf79ce1f4e311c4ff3d0f8894de SHA-256: 6cc4c9d6b9d21c0a6fa8aede3af41433020921bb68505e294338dfdccec000a8
206 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a phishing or malware distribution campaign, as indicated by the 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The document contains numerous external links, including 'https://vilenefex.ru/123?utm_term=aviation+security+book+pdf', which likely serve as lures to malicious websites or for downloading further payloads. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • 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 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://vilenefex.ru/123?utm_term=aviation+security+book+pdf
    • https://static.s123-cdn-static.com/uploads/4501028/normal_5fe3de174477b.pdf
    • https://cdn.sqhk.co/salasereki/giidmQA/hockey_goalie_training_near_me.pdf
    • https://cdn-cms.f-static.net/uploads/4453729/normal_603c1d1949ddc.pdf
    • https://cdn.sqhk.co/limiwebu/jiaDKic/resuzixoxozedudegixu.pdf
    • http://mixed-rootwork.com/purchase_requisition_letter_template5xwao.pdf
    • https://static.s123-cdn-static.com/uploads/4465128/normal_5fe4e695074dc.pdf
    • https://static.s123-cdn-static.com/uploads/4374199/normal_5fcd00accf590.pdf
    • http://natlab.ru/how_much_does_a_crown_pallet_jack_costrteyl.pdf
    • http://drive4mclaneaustell.com/aafco_approved_dog_food_brands_list9f58d.pdf
    • https://cdn.sqhk.co/tijanukubo/YshKghm/vexaxosovo.pdf
    • https://cdn.sqhk.co/lisakopew/ihcWghA/lugow.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://c63ca81c-6df4-4ec3-bc2e-8508f29a6879.filesusr.com/ugd/d48fe3_269c09fd2aeb4a47b64acd7f4362a705.pdf?index=true
    • https://4590046d-f0a9-4171-b8a0-56ff8c1fe63c.filesusr.com/ugd/0bfb20_66784175d81949488474562777d356db.pdf?index=true
    • https://c81c1a69-aec6-471c-ac34-7a6800eafc69.filesusr.com/ugd/9ef1ea_4434e2a470724c0ca5b72d7781061694.pdf?index=true
    • https://s3.amazonaws.com/batoragubukepo/zakegepunexurakuluja.pdf
    • https://4c2674ec-1430-4cec-a455-d6a35d10586e.filesusr.com/ugd/38955b_1ce2f034fea948a99e9b50656b2d51f0.pdf?index=true
    • https://s3.amazonaws.com/jigezilor/81378957821.pdf
    • https://d2ea4bfc-f92a-4379-acf2-d9b69981ddb7.filesusr.com/ugd/739437_85bc029e0fe34c64810fc38af7f380f1.pdf?index=true
    • https://4cf6c2b4-cd84-4b73-83b1-bf7f441162b2.filesusr.com/ugd/e50c99_854f287016f247bdbf5d24ede4d0bd18.pdf?index=true
    • https://s3.amazonaws.com/besafefaf/philips_shaver_heads_series_5000.pdf
    • https://7605c768-a471-4169-85a9-0dab509fd250.filesusr.com/ugd/20ab23_3628fa7d1df1441c8f0387b14e206ef4.pdf?index=true
    • https://15319a82-8c66-4906-b3c2-464277991f2b.filesusr.com/ugd/070acf_9dab756762db4f1a8906bdda763667ee.pdf?index=true
    • https://92fbd7ca-8480-4723-bb2c-19523f9dca15.filesusr.com/ugd/29946e_11e848c9246f40a6815663f0141ef3c9.pdf?index=true
    • https://s3.amazonaws.com/baxegezivumi/tamebiwuvufoju.pdf
    • https://30dce114-5b7d-4ba4-aa44-e083516804ec.filesusr.com/ugd/7de0fd_fe2ea8ed321a4c39a0e019982de3182c.pdf?index=true
    • 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/
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2d3.bin
f5d04910ad80df3738cfb0be3d0e834a4c9de0f80da4e6adf27c17160ed3f7a8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D3 5356 bytes
font_01_sfnt_off0001051c.bin
4e5d8d9d2eb92ab4d86276ee8e5bf0bf3a548a38c427c95d98a7f0a6245e735d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1051C 11412 bytes
font_02_sfnt_off00012ba5.bin
b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BA5 4324 bytes