Malicious PDF — malware analysis report

Static analysis result for SHA-256 33559ccf0aba1dc2…

MALICIOUS

PDF

79.9 KB Created: 2021-09-19 17:50:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eaef624e83d048d1327013505c0a40c0 SHA-1: 44b247d5668ba47326d0219880a7e54180c3872f SHA-256: 33559ccf0aba1dc21fabec8d5f9e58efea6840b7beeb805eb0dc84cdf606bfd8
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external sites, many of which appear to be compromised WordPress uploads, suggesting a link farm designed to distribute malware. The presence of a 'Password-protected archive handoff' heuristic indicates the document likely instructs the user to download an archive, for which the password would be provided, a common tactic to bypass gateway security. ClamAV detection further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://laborke.ru/uplcv?utm_term=descargar+certificado+digital+en+android
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/7fc3a7d96aaec050390a5098bc83e02b/73225843882.pdf
    • https://sainaudit.mn/File/ruziguxogusadinopadubedu.pdf
    • https://szabobuszberles.hu/files/files/22669197794.pdf
    • http://duocmyphamcongty.com/app/webroot/uploads/files/23566580032.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/3961b548c1d387dbef0b2a2c45964bee/rokolerudolumeruwari.pdf
    • http://nuovojob.com/userfiles/files/romudavikoparidak.pdf
    • http://homestationrealty.com/userfiles/files/64999680312.pdf
    • http://globalfeedindustry.com/upload/files/tetozebu.pdf
    • http://finemetal-cn.com/upload/files/lajomupifexamivalug.pdf
    • http://sujitonweb.com/userfiles/files/96053615563.pdf
    • http://archpiudue.com/userfiles/files/73089886383.pdf
    • http://halongwave.com/userfiles/file/dusovuguxazabebazodoxewo.pdf
    • http://www.hgbehringer.de/img/files/files/23337967034.pdf
    • https://wfbulgaria.com/uploads/wysiwyg/files/65853161814.pdf
    • https://houstoncoinclub.org/FCKeditor/file/paderelerelisadilitagux.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a2dbeec99d---jozasajuvek.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141819ebcdf3---80567644384.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/pev7d91nlv6n00mktcceh1heun/rorusopisuvisax.pdf
    • http://husplaza.hu/editor_up/bafojupuvu.pdf
    • http://elitakhealing.com/ckfinder/userfiles/files/vodufukizav.pdf
    • http://www.bc-arman.kz/ckfinder/userfiles/files/gujari.pdf
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/32692745594.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/f4o5k31d7f6nkc6fdp3akkdbps/40910006487.pdf
    • https://408of53crownstreet.com/assets/media/files/zirajisukaxosorusonusu.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_off0000d373.bin
8dc9e26e2bef176a96ffb4746cff74ae17f74ba5b582587d1d6c5e1cbf03bfe8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD373 10652 bytes
font_01_sfnt_off0000ebc6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC6 16792 bytes
font_02_sfnt_off000103d8.bin
a8a6170a7912afc777e82c5668dbd03e72a7b34e8dc0f4e91a68d2c52d93c371
pdf-font-stream PDF embedded font (sfnt) at offset 0x103D8 18076 bytes