Malicious PDF — malware analysis report

Static analysis result for SHA-256 86733820c2374cd3…

MALICIOUS

PDF

68.8 KB Created: 2021-04-12 03:02:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6cd5dd3dd51e32214bc25b38ee6eb2c9 SHA-1: 7aa604b9ea2a830a6e0c5320f4d6bf33cb6c7353 SHA-256: 86733820c2374cd375585cecf446b232786cc427a84cbccaa16688aa7114b525
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which are disguised as academic or book-related content, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and numerous external URLs point towards an attempt to redirect users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=author%2527s+purpose+worksheet+4+answer+key
    • https://cdn-cms.f-static.net/uploads/4377663/normal_5fd78265409d5.pdf
    • http://vukojekan.mypressonline.com/chokher_bali_book_bangla.pdf
    • http://vibijinit.scienceontheweb.net/forced_marriage_urdu_romantic_novels.pdf
    • https://cdn-cms.f-static.net/uploads/4451750/normal_5fdb947c24092.pdf
    • https://cdn-cms.f-static.net/uploads/4416512/normal_6023fef7c60ec.pdf
    • https://static.s123-cdn-static.com/uploads/4490250/normal_5ffa5d270e2d6.pdf
    • https://static.s123-cdn-static.com/uploads/4365575/normal_5fdf62d4dc542.pdf
    • http://ralugugifoxatir.scienceontheweb.net/6542106571.pdf
    • https://cdn-cms.f-static.net/uploads/4479710/normal_5fe6433f0033d.pdf
    • https://cdn-cms.f-static.net/uploads/4463794/normal_601ad455f1453.pdf
    • https://cdn-cms.f-static.net/uploads/4426822/normal_6042e94636dbe.pdf
    • https://cdn-cms.f-static.net/uploads/4451356/normal_6069c8dcd0c6f.pdf
    • https://static.s123-cdn-static.com/uploads/4425515/normal_5fe01c091dcde.pdf
    • https://cdn-cms.f-static.net/uploads/4411714/normal_60688b7c8b3e7.pdf
    • https://cdn-cms.f-static.net/uploads/4465924/normal_600e9e566726f.pdf
    • https://cdn-cms.f-static.net/uploads/4415534/normal_60307b6b85440.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/fejififimaketo/age_of_exploration_worksheets.pdf
    • https://s3.amazonaws.com/bejenosugede/88254792929.pdf
    • https://765a5d72-5774-4a4d-a421-5c90307110ba.filesusr.com/ugd/f2a868_e1e974b3f05c4c0a886f5e63c7fe4e31.pdf?index=true
    • https://8cff94d3-ecab-4ea5-ad27-d3e67d02fd32.filesusr.com/ugd/2813e2_d563965685e7455fa8ad78e73ae54e55.pdf?index=true
    • https://90138cf2-752b-46b9-a396-1872e0473e42.filesusr.com/ugd/02203e_13adb4eb2f9040098048984591495270.pdf?index=true
    • https://s3.amazonaws.com/midipes/nofaganezofisep.pdf
    • https://s3.amazonaws.com/kisimujuk/foil_in_romeo_and_juliet_act_1_scene_1.pdf
    • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1c3.bin
783ebe10dbad8ec576ceee8869691f7d8cb46a0e8ad5ccb95a487b06d15b1269
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1C3 5244 bytes
font_01_sfnt_off0000e3b4.bin
915c82f7ecd69fee91a568db649440491c69ea4db69b9e462e17c37f95a8e8aa
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B4 9900 bytes