Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef6340d092bdd697…

MALICIOUS

PDF

84.8 KB Created: 2021-07-04 23:45:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c735ef306a8487ec709d668c4ad7d5a3 SHA-1: 7fe2780716f24828772afc2498c73d430868e453 SHA-256: ef6340d092bdd697e7410925ce3e90dec2a5b36b71facbd8c0ae3afa6b535bd6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites, often initiated via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9962

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://kstarsmall.net/userfiles/file///bugifobipu.pdf
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/e236b7e6c13634119597e79b21bc3586/7814590839.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c41a6bc6ba6---tajixutelomovefope.pdf
    • http://xn--80an2aej.xn--p1ai/up/file/nurupig.pdf
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/16091feb715fe8---lipejane.pdf
    • https://kraftyz.in/ckfinder/userfiles/files/41279268850.pdf
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/aa40e064c6113fd717d806fead300eb2/4679930446.pdf
    • http://amandamaitland.com/images/file/36827271574.pdf
    • http://standartbio.com/fckfiles/file/tobafubif.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160710dac13a2d---sovavuxu.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16098481a643c1---nofonevuwutoxagusev.pdf
    • http://provia-events.de/pics/fotos/1/file/29647276047.pdf
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/0bc5d1aa817b59ba835cd8fdc9ad5c90/18580713066.pdf
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/b0918ee405adac3293c1f762d2a84ea7/32195520206.pdf
    • http://cjandjunemillerfarm.com/clients/75830/File/vuverareladeburedibugad.pdf
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/6073a787628a8fd2c4dd4918c3db85e6/29250382313.pdf
    • https://ratsimae.ee/media/contents/file/75494792594.pdf
    • http://birzebbugastpetersfc.com/files/file/19890607000.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/v35ijfl63uhe66dkn0n5hhjmau/jimeviravuzogi.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160925ae7dcec6---xevidafuvanixupude.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b462aef5bd---vazuwawakifebi.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608183288c099---pefaturolomalofebaduka.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=outlook+data+file+cannot+be+accessed+office+365
    • 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_off0000e584.bin
2816b1ce3657906ad0eb5260420d9d661fc0e073c294606b1a2c50e43233219a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE584 11200 bytes
font_01_sfnt_off0000ffdd.bin
49e7b1f72b5e5220f3ce5a9ddcbd8015ce4dba97173daa2c81c4ce501e49553e
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDD 17460 bytes
font_02_sfnt_off00012dad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DAD 16792 bytes