Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53e9ceb9e641bc3…

MALICIOUS

PDF

89.0 KB Created: 2021-08-05 23:24:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87849e777d3dcd4cf847f5132090b22c SHA-1: 1bf305ffa31ae3ce51bc8922fea89f7a2a68eb79 SHA-256: a53e9ceb9e641bc3ad3df7114505ccaad55a12b8d2a619c6d2f18a43f5273349
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload is intended. No scripts were extracted, but the heuristic firings and URL analysis point to a malicious document likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://oniceh.ru/uplcv?utm_term=easy+fluffy+slime+recipe+without+borax+or+glue
    • http://stlnsk.ru/uploads/file/wipewakup.pdf
    • https://mokhalasati.com/userfiles/files/fodupofutefavikupusa.pdf
    • http://baikalspring.ru/ckfinder/userfiles/files/kanibed.pdf
    • https://africanresearchcenter.com/userfiles/file/24040097817.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075f619c19b2---37156329734.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec88b79dd9---mopivaxefopa.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/de9de22f664a04a8cf1c39a83f59d08c/94084480727.pdf
    • http://barrybusiness-crm.com/ressource/devis-photo/files/xowugotevezetu.pdf
    • https://vibangnhadat.com/uploads/files/83145311275.pdf
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/9jfkrdh3a66abccqe99h2s5p64/2629044570.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/l1ujv0hoo4r38hortta3k3nbs3/29190954027.pdf
    • http://anhuifan.com/upload_fck/file/2021-5-30/20210530073803724263.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/u22o28jdhsjqtkia70r6hpbf10/52844888162.pdf
    • https://primer-spb.ru/files/files/88490681402.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a44347329b8---supimipireju.pdf
    • https://blindnow.com/userfiles/file/finavabarepor.pdf
    • https://caribemed.com/userfiles/file/kofoponojiwadoborosodefos.pdf
    • http://orchid-daikanyama.com/userfiles/file/palav.pdf
    • https://minipowerpack.net/upload/files/69565158679.pdf
    • http://izumrud38.com/ckfinder/userfiles/files/22726001366.pdf
    • http://wo-kop.pl/userfiles/file/65348451370.pdf
    • https://alohasafaris.com/files/dovunutuwemilelowuzede.pdf
    • https://maturana.cl/upload/file/vifunozijisafegiwop.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5e14cf3ed1bf7df248219c3ac208f174/39054641829.pdf
    • http://bhavalaya.org/ckfinder/userfiles/files/rixowalonomemeku.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f609.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF609 16792 bytes
font_01_sfnt_off00010e20.bin
e44e8f104986bcca53e54b3d516210e158ba2b9648bea26064947fbc883a0c0f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E20 11348 bytes
font_02_sfnt_off000128bb.bin
e7cefc53fa311a8017dc97ca04f9f4abaf60cf4b91143dc3440224d51eecd18a
pdf-font-stream PDF embedded font (sfnt) at offset 0x128BB 17016 bytes