Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9e11f12f3fbb7de…

MALICIOUS

PDF

74.6 KB Created: 2021-06-10 18:29:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ecafe2d1483cc006b2228fa5ab9f0011 SHA-1: cef7367a647c57c98c5726e9bfc9ea665ff099ed SHA-256: a9e11f12f3fbb7ded4cd8fcf091d42023d26fdaf1031525e929afea9380bc3ab
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains heuristics indicating it is a link farm designed for SEO, with numerous external links. The document body, though partially corrupted, suggests a lure related to 'Airtel postpaid bill payment receipt format', aligning with phishing or scam tactics. The presence of ML and ClamAV detections, along with the link farm behavior, strongly suggests malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 8

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://drafthe.ru/pbw?utm_term=airtel+postpaid+bill+payment+receipt+format
    • https://tujelogujonugi.weebly.com/uploads/1/3/4/4/134491942/9c486defd.pdf
    • https://cdn-cms.f-static.net/uploads/4390374/normal_6027a53422bec.pdf
    • https://tanavizone.weebly.com/uploads/1/3/4/7/134709943/6058744.pdf
    • https://cdn-cms.f-static.net/uploads/4496378/normal_604985f10b62f.pdf
    • https://turetufifej.weebly.com/uploads/1/3/4/5/134500159/2883624.pdf
    • https://wopaxosidavi.weebly.com/uploads/1/3/4/7/134732603/kujelur_nanojanafi_sofetevefi_vokisi.pdf
    • https://wipamixupes.weebly.com/uploads/1/3/4/4/134460990/acdd87ec.pdf
    • https://pavadugubuwab.weebly.com/uploads/1/3/4/3/134309483/d92fcd938fc.pdf
    • https://cdn-cms.f-static.net/uploads/4459164/normal_6025b7fb5e864.pdf
    • https://cdn-cms.f-static.net/uploads/4391013/normal_601af80e1bca4.pdf
    • https://peninugeba.weebly.com/uploads/1/3/4/6/134666339/lasegufajusizobewob.pdf
    • https://bemetezebore.weebly.com/uploads/1/3/4/8/134882820/61b8d871dd.pdf
    • https://zozutogumudeke.weebly.com/uploads/1/3/4/4/134440166/xeneg-setawutijobeja-bumovuk.pdf
    • https://ximuwiwafit.weebly.com/uploads/1/3/4/8/134851464/gujezidobazewapa.pdf
    • https://zogazipo.weebly.com/uploads/1/3/2/3/132303407/nebaninizi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://lakiluxodev.pbworks.com/f/98956558745.pdf
    • http://xuruzinijub.pbworks.com/f/3d_parallax_live_wallpaper_apk.pdf
    • https://uploads.strikinglycdn.com/files/138b614b-de1b-413d-98c2-36ded4f5bd67/maytag_quiet_series_300_touchpad_not_working.pdf
    • http://fuzobonesujo.pbworks.com/w/file/fetch/144564243/39002958574.pdf
    • https://uploads.strikinglycdn.com/files/541c2aac-ae48-4f2e-aad7-dfba5c17302a/how_to_find_perimeter_of_similar_triangles.pdf
    • https://uploads.strikinglycdn.com/files/58509d5d-181c-446e-a783-a37a3c7a9297/pasezixufonezejexu.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3e4.bin
5ccdb28e3fb9c1e724c47b4c1d537665eae7b17c0c3a90613e028d9bdb2987d0
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E4 5532 bytes
font_01_sfnt_off0000f6a0.bin
d696042a329bd98d5b192f21a7b80b22dd2713a87b9dd22fe1cca0fbbe11d106
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A0 11260 bytes