Malicious PDF — malware analysis report

Static analysis result for SHA-256 aab1c879e74e8331…

MALICIOUS

PDF

110.4 KB Created: 2021-06-27 17:44:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 287bb06f8b101de7c664d24d014b3d78 SHA-1: 862dc6d3e1f82892f53949910f64772f2c1adac5 SHA-256: aab1c879e74e83312fba13ab9c6335612a56a4812b4b8cdf5c4eddc47ac29886
216 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a fake CAPTCHA prompt and a link farm pointing to compromised CMS uploads. The document's content, though heavily obfuscated in the provided excerpt, likely serves as a lure for a phishing or tech-support scam, prompting users to interact with malicious links. The presence of numerous URLs hosted on potentially disposable or compromised domains reinforces the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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.
  • 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.
  • 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://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/mukomojabojuwizive.pdf
    • http://modellszerviz.hu/userfiles/file/271284963.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8710ec8d9d---53690407666.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/98f6ba99feadcaeb9929cf0efce7085a/vomofekafosum.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16083ebecb1dbf---1875132170.pdf
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/23jnaj9vc67go8205sf2mkq77f/tovumorazo.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f3f7d4cac---3336846926.pdf
    • http://rubivina.com/Images_upload/files/batepureno.pdf
    • http://infinivideo.hu/sites/infinivideo/files/kapilafavuzisowukosajabur.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/a3ebf6945875603868cd0de62cfce7fa/57826677936.pdf
    • http://denis-lefebvre-services.com/fichiers/file/rejivapufikobemuvazog.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606fbbbb8ffac---10448986113.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160764ec24af2f---56353415784.pdf
    • https://rzfmuhasebe.com/userfiles/file/11545420121.pdf
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdef4a1334---4676780325.pdf
    • http://chnli.tw/CKEdit/upload/files/belomotadabadazajuxolol.pdf
    • http://pnmanagementsolutions.in/uploads/dukofuxakewowotudopejufaf.pdf
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/9n7ampktgu1h7gm19vsl57mli3/37960295941.pdf
    • http://teplospectr.ru/images/files/48102499833.pdf
    • http://www.asslar.de/downloads/48249505375.pdf
    • http://podlahypilat.cz/admin/file/xedazidasudokavenas.pdf
    • https://evpersoneli.net/ev-personeli/file/simov.pdf
    • http://peusch.lu/userfiles/files/sovexudukosiverotiwoxaz.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=cultural+diffusion+in+a+sentence
    • 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_off00014984.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14984 16792 bytes
font_01_sfnt_off00016196.bin
42e4edbeb6127fd91bbff5af5732321f67f09eb0485b37ae37f723548c61f09b
pdf-font-stream PDF embedded font (sfnt) at offset 0x16196 19700 bytes
font_02_sfnt_off000193f1.bin
966e422fe6ad15dc7393c9afd9a618a29ad394d2b287d9b931e36255d6ec1a6d
pdf-font-stream PDF embedded font (sfnt) at offset 0x193F1 10600 bytes