Malicious PDF — malware analysis report

Static analysis result for SHA-256 38910ea37c22183a…

MALICIOUS

PDF

77.4 KB Created: 2021-06-18 13:01:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: cb6d2bd004687e118503dc043d6fa9a3 SHA-1: e07a4ef00fc81310fd9cb8fb2fccb315c9ff3cac SHA-256: 38910ea37c22183aae2b6b36c715531196fb8ecf739dcb8c5ff034a90877590b
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 WordPress sites utilizing form builder plugins for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be junk data, but the presence of link farms on potentially compromised infrastructure suggests a phishing or SEO poisoning attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a3eb772c21c---59346685728.pdf In PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160724bb646816---tomadedisijelomijodu.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160aa83508dfd3---kijawaxopov.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/c6b7c3cdb4dbae0e3acfdc00225d9ecf/96100176912.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a791ff378fd---forawedejib.pdfIn PDF document text
    • https://fourseasons.events/wp-content/plugins/super-forms/uploads/php/files/c9b781dc01e5c97553a9472c5f334920/fuwibuvefoteku.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086aa30e497c---22041240563.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609279e1a8698---gofasubigipevaxatog.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/nusarizupijav.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/774oo0c40j3ksp75po8o5t6oa7/lutezasifutalasiba.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/giwegivimewenaxeropuwekoz.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/4b916f71ef201e5763884669b052451e/96425142909.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607346e4e25ef---sirujewamodowesazatir.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/80899478189.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=naked+mature+women+smokingPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F1 5240 bytes
SHA-256: 3d2e5b582428a919a0480cb0a4006f74e6515592163d9e088a6ea32500cba977
font_01_sfnt_off000105c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C3 10308 bytes
SHA-256: 09552b2c35fd0f8b1bf7924a3796c70edb4327a2422b195728ff50e901031371