Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c3e3f8ad5cbc85…

MALICIOUS

PDF

80.3 KB Created: 2021-06-01 20:16:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 9c896f07e6ec6a39dea0710cebc9f693 SHA-1: e873e723f246ec85ae9e01299a86303cb9c043bc SHA-256: 31c3e3f8ad5cbc850edda197e0a9daae5aec0b1aafdfcf9e1042847bbadeb645
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://archism.ru/pbw?utm_term=simple+present+reading+comprehension+exercises+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4463002/normal_6030507419779.pdfIn PDF document text
    • https://vegivuben.weebly.com/uploads/1/3/4/6/134660922/2092bc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426415/normal_60110192e0fab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484804/normal_605a48dfcedd2.pdfIn PDF document text
    • https://nasuvanebi.weebly.com/uploads/1/3/5/3/135393195/godik.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410214/normal_602104cb15f3a.pdfIn PDF document text
    • https://kosazuritejozu.weebly.com/uploads/1/3/0/8/130874521/dejozi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385848/normal_5ff2d69b3fe93.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411512/normal_60443f22e640b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386076/normal_6021f9b9e11d7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502188/normal_6011e7e2c2611.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387424/normal_5feb823744922.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392457/normal_602ee04f9579c.pdfIn PDF document text
    • https://dowezepuxaku.weebly.com/uploads/1/3/4/4/134463959/1619316.pdfIn PDF document text
    • https://jifabipesetumef.weebly.com/uploads/1/3/4/8/134896168/pewodojuruwuduzat.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471455/normal_5fe74b70ef392.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417818/normal_5ff219c545332.pdfIn PDF document text
    • https://dutegonuguval.weebly.com/uploads/1/3/4/3/134310875/7074853.pdfIn PDF document text
    • https://fuvutefimege.weebly.com/uploads/1/3/1/4/131453053/90630d7d.pdfIn PDF document text
    • https://xusukimijep.weebly.com/uploads/1/3/2/6/132681495/143a84be74.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/7f8c6ca5-075f-4768-af0e-0e9fd92e0753/baby_einstein_neptune_jumper_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb5b961e-e6a3-4b53-b992-1b661c1acdf1/2007_dodge_caliber_transmission_service.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/174ec364-5e2a-483b-8c30-416bdf1b3a82/ruxapitebi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/53e0385f-b9a0-4c1b-ab7d-4e5732bd69de/safety_glasses_over_prescription_lenses.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e4eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EB 5740 bytes
SHA-256: f320ee0c10f961864c9ea03f0aa8d87e8a7cf315c46c9bda796f97a9bceff17d
font_01_sfnt_off0000f84f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84F 10316 bytes
SHA-256: a1a677fc9aea5ad271d3035206883f6d8af62dd212646e6fdf025db2b9df9af4
font_02_sfnt_off00011bbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBD 16204 bytes
SHA-256: 541fa2b6826b0add99b7d5a173ef1e6a5567607b5192f75b810eb17d6a563501