Malicious PDF — malware analysis report

Static analysis result for SHA-256 a490f8193cb2e960…

MALICIOUS

PDF

93.7 KB Created: 2021-07-13 04:02:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6bc600167bdfb38759da259ed3eff869 SHA-1: 1ef2d6d5ea3bd128c4f552cf5bf128d1a51d8a84 SHA-256: a490f8193cb2e960612f6da18cc7feabc33ef5236afe58c42f33fe452cf8aad5
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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
  • 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 http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/4a3db3601b7157876b5f7a878137d767/39907733518.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160988a9b73e4d---dujumugedozenifirafeji.pdf
    • https://bandotrading.com/uploads/file/14623683986.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160cae7901f027---46080948332.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/lottj501db1lk5afgfv6ocnnkf/tujujemuri.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-5-15/20210515190931817974.pdf
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a31df464ae---gitotomegurarami.pdf
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/82057ff1ed2c86094efaaafe73e80ede/puxekejutowu.pdf
    • http://srub-servis.ru/userfiles/file/fiwewepoputixomilosa.pdf
    • https://floridainvestment.cz/files/file/rujizejopi.pdf
    • http://oikoscoccatoarchitettura.com/userfiles/files/xoratomujiduzemumom.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/mcncang9vto9igik12j83h7nl3/91562961328.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/e9v9hrtc50npe245nejqif69mo/berogawuse.pdf
    • http://kasystemofkarate.com/clients/861259/File/mefadakupuxiretege.pdf
    • https://pioneerlift.com/upfiles/editor/files/kugad.pdf
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16081755bd7b51---7483721323.pdf
    • http://sola-brothers.com/userfiles/file/84206470772.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/bc0f2437ee9c4fcbe2e627ced0224628/poviv.pdf
    • http://www.impactit.in/ckfinder/userfiles/files/katov.pdf
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/fqeeskcuceto2l1q27lrtmv04g/davubur.pdf
    • http://funperm.ru/content/file/sipugegunazididuzux.pdf
    • http://reversetheclocknow.com/ckfinder/userfiles/files/zoxofejuwafadulaw.pdf
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1a92105f6---6307781955.pdf
    • http://abogadosaguilar.com/ckfinder/userfiles/files/pubudopojixofugub.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=commercial+well+drilling
    • 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_off00010985.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10985 16792 bytes
font_01_sfnt_off00012197.bin
f0c9bd653aa63291421733a6de748dd0bf021a824063fac4f50600864dad42e5
pdf-font-stream PDF embedded font (sfnt) at offset 0x12197 18992 bytes
font_02_sfnt_off00015218.bin
c28d0dca9e014aaa2be41f0bc2335f41a9f8bf8accff750a004cde658591a0de
pdf-font-stream PDF embedded font (sfnt) at offset 0x15218 10564 bytes