Malicious PDF — malware analysis report

Static analysis result for SHA-256 859e64f4437eefbf…

MALICIOUS

PDF

84.3 KB Created: 2021-10-07 17:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6cb95fdbdcadd9e3136901decbf0fb0f SHA-1: b0eb7084e714662267519360bbeedd8da1e166c9 SHA-256: 859e64f4437eefbf2dfc0d40c9abcf78e0fc1b04e130c9541d8715d0214ca350
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://pistant.ru/uplcv?utm_term=carbon+footprint+of+the+internet+2020
    • http://burmeseburmilla-allevamento.com/userfiles/files/6048177538.pdf
    • http://schokofontaene.de/idata/kerame.pdf
    • http://abw10thstreetne.com/uploads/files/daxogafupe.pdf
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16151b07c120d7---68007825369.pdf
    • http://worshipedia.mobi/sites/default/files/file/gatulibukon.pdf
    • http://medicareclinichowrah.net/faboriginelist-braj/userfiles/file/49697522257.pdf
    • http://quocteanviet.com/img-chamthi/files/xenurifigaki.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161416a7c10436---lufajatunufenewexobenov.pdf
    • http://denprokhorov.ru/images/file/97284119788.pdf
    • https://praktijk.zorglink.nl/ckfinder/userfiles/files/88481609007.pdf
    • http://thegioimercedes.com/upload/files/68308699605.pdf
    • http://slenderclub.cz/ckfinder/userfiles/files/10222940711.pdf
    • http://gymostrov.org/gymostrov/userfiles/file/32764251180.pdf
    • http://craft-personal.de/userfiles/file/50944813576.pdf
    • http://laihoawedding.com/app/webroot/upload/files/29088659568.pdf
    • https://infracsap.hu/files/file/mudam.pdf
    • http://perchegouet.com/ckfinder/userfiles/files/xidujagesa.pdf
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/waxoridigazu.pdf
    • https://mountmoriahcamp.com/media/12711985672.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/l436c32sboneba40p5oso246to/63627256654.pdf
    • http://rockefellersgold.hu/editor_up/49843334884.pdf
    • http://www.trisad.kz/ckfinder/userfiles/files/radojowotipuxokov.pdf
    • https://emotionalgift.com/ckfinder/userfiles/files/9920885805.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_off0000e041.bin
c5fcc852a9a33747bce74bbe3aad24c243cc1c7e5e3088261895bdd79b43fbfc
pdf-font-stream PDF embedded font (sfnt) at offset 0xE041 10656 bytes
font_01_sfnt_off0000f868.bin
fabdc821439dc2ea91c18696df3739ffa9df41a0823d5038b8f58eb3c02891a3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF868 19596 bytes
font_02_sfnt_off00012bb3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BB3 16792 bytes