Malicious PDF — malware analysis report

Static analysis result for SHA-256 363a05c81ba5a20e…

MALICIOUS

PDF

72.8 KB Created: 2021-09-09 20:55:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 340d50359504ef407036f60a740bba98 SHA-1: f5ed3e851e2b3466b22d5cf62d491c8b712262ec SHA-256: 363a05c81ba5a20e45ad9d750d02a8cfab7f5886152c79336f4acb22f969a16d
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating malicious intent, including random URL links and a link farm on disposable hosting, suggesting it's part of a phishing or scam campaign. The presence of a download button lure and a callback lure further supports this, aiming to trick the user into downloading a secondary payload. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with known malicious PDF droppers.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://rivebistro.net/ckfinder/userfiles/files/31322028304.pdf
    • http://altiro.nl/home/tjerk/file/68628905257.pdf
    • http://simonide.org/userfiles/file/21993993805.pdf
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/diluru.pdf
    • http://tianlanlawyer.com/filespath/files/20210904140331.pdf
    • http://giayviettri.com/img-ftec/files/werodemakejivata.pdf
    • http://kimbuunguyen.com/uploads/userfiles/file/ramisabapujipawe.pdf
    • http://islaminkiel.de/webmisr/uploadwebmisr/file/29851816521.pdf
    • http://origo.ws/userfiles/file/rivaveguxurevos.pdf
    • https://2b3la571ga-70p.com/contents/files/87029898762.pdf
    • http://gzhangqin.com/uploadfile/files/nawigukoxep.pdf
    • https://99shayari.in/userfiles/files/46109791988.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372a579f5af---doxetimilijumalefowo.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/c768817c1dc519e016e56dd3f7a1404f/82295196540.pdf
    • http://rund.cz/UserFiles/File/potenajiz.pdf
    • http://cuacuonanbinh.com/userfiles/file/zijemorisedixinimisu.pdf
    • http://alfonsoguiggiarchitetto.it/userfiles/files/mejefuf.pdf
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/91352405329.pdf
    • https://topinsolventa.ro/userfiles/file/87460288572.pdf
    • https://kalyna.ua/sites/default/files/userfiles/file/pajomejezivomugidabuna.pdf
    • http://bbbo.handyfriendship.com/upload/files/50664166268.pdf
    • http://dpholding.ru/uploads/files/6063912531.pdf
    • http://waxiangyuan.com/upload_fck/file/2021-9-5/20210905033213743564.pdf
    • http://skazka76.ru/pic/userfile/11166647974.pdf
    • https://samirkumarpaul.com/ckfinder/userfiles/files/fawalegafuxirobabotajotiw.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=manje+bistre+full+movie+online
    • 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_off0000b837.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB837 16792 bytes
font_01_sfnt_off0000d04e.bin
322d9aa682076ea6dfa75f605fc4c03b515e195ae341bd27090b4e36430ba7a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD04E 10804 bytes
font_02_sfnt_off0000e932.bin
806a18f77ada91263846cc10d372a0481c1b0da78b5eeff360dd42c23e220513
pdf-font-stream PDF embedded font (sfnt) at offset 0xE932 17280 bytes