Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d1a724919e2b97…

MALICIOUS

PDF

83.6 KB Created: 2021-09-19 13:55:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 23805065015447dfbc803e6298583a1a SHA-1: 4f41766a1ea284ebf1cf9805c026559b1acc7583 SHA-256: 31d1a724919e2b974a898373fa2f06e8a6d94f00d78cfae81ffe75d64b03bbfb
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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.ctmmaximoravenna.com/ckfinder/userfiles/files/milijajodekufape.pdf
    • https://monographie.com/ckfinder/userfiles/files/pewovodofatazogog.pdf
    • http://aasghsflqsae.handylover.com/upload/files/wadimutexasijamedawejeve.pdf
    • https://optimustelecoms.com/ckfinder/userfiles/files/75820196293.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/881e033f674e211371a53a21e86cceed/javejomug.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613034d613a36---7977551837.pdf
    • https://xn--fiqa735be48e.com/upload/files/59477108006.pdf
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/v621uhu0chchroq40qgb6tjc2g/vidafesenazumov.pdf
    • https://itexpertdog.com/upload/files/rinagodosovapuvi.pdf
    • https://2b3la571ga-70p.com/contents/files/rowalifimedubajovanifezu.pdf
    • http://fsnmmaterials.com/UPFILE/userfiles/files/vivuvikagebasi.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161402d087e383---sosorigukadi.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2730115ab---66295539764.pdf
    • http://oralrem.kz/ckfinder/userfiles/files/33077318638.pdf
    • http://damosushipleasanthill.com/uploads/files/51292342146.pdf
    • https://inprovitecuador.com/ckfinder/userfiles/files/95786643722.pdf
    • https://istanajp2.com/contents/files/52066212040.pdf
    • https://ev-owners.jp/userfiles/files/99625795344.pdf
    • https://gym-rectif.fr/ckfinder/userfiles/files/gulosarujuga.pdf
    • http://mazraeir.com/images/upload/files/bazopujumudowezulawuval.pdf
    • http://luisacortesearchitetto.it/userfiles/files/76470645456.pdf
    • http://chaitraglaze.com/uploads/bopelipikurigulo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=mope+io+free
    • 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_off0000e4d3.bin
4dade1d51b5a6afacda52b40f0788f0bfa19b28aeadc1f7f7edca2ce47a69f84
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D3 18008 bytes
font_01_sfnt_off000113c9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113C9 16792 bytes
font_02_sfnt_off00012bdf.bin
57fe8a05882e7d1a667e98d942a72116c32517bd02d6668d1cd31d9c614f48d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BDF 9764 bytes