Malicious PDF — malware analysis report

Static analysis result for SHA-256 31accec6cd6afc44…

MALICIOUS

PDF

94.9 KB Created: 2021-06-27 09:31:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b344ff469321213e0c856ba12a1bbc60 SHA-1: 010c0028e94573515759247a67320e946004ca88 SHA-256: 31accec6cd6afc448ab72ad7f2ee79dc90b5a46ffe2d3ca2da1269930e814512
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and potentially malicious domains. The presence of external URIs and link farms suggests an attempt to redirect users to phishing or malware-hosting sites, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://crysiq.ru/uplcv?utm_term=purchasing+interview+answers
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/ak8o0uib9r1t9p8v9bjm5rak51/gozorotowimizoxepofuboz.pdf
    • http://glenbrooksouth1970.com/clients/1/17/17fc1bd13d5538a69f39d58c869d2fc5/File/suboxijodefus.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607b32654a7bb---kedebivesupo.pdf
    • http://mastera-mix.ru/ckfinder/userfiles/files/gidosironudunonugevel.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a593174c91a---rapudejokevaxasasi.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d34b09d88a2---pugof.pdf
    • https://nutricount.cz/UserFiles/File/mikajitilifozuxenofevo.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9e0f0b5ec---topeparevovuwad.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c223b73e933---40654587607.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c58097da2d---43831052294.pdf
    • https://atcotourismtravel.com/userfiles/file/likirugenenelilezajuk.pdf
    • http://pozitron-s.ru/userfiles/file/97271242150.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d5bfc5efd---nuvokugakelanep.pdf
    • http://ttmplus.com/userfiles/files/tudanugazugezejidinu.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/23653bdaa1e19e457fedec525527086d/83421852702.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608014860d768---32066296415.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b9055945b81---22598435653.pdf
    • https://binarbaid.com/public_html/userfiles/file/57312584531.pdf
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094b44cabb1d---51752810260.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c6dc045fc5b---49738921568.pdf
    • https://aimara-bg.com/userfiles/file/pisagupuduzukoroku.pdf
    • http://fitviewer.biz/files/file/malavexemivevozupod.pdf
    • https://akproauto.com/nbloom/fckuploads/file/4920358401.pdf
    • http://akcjonariusz.com/UserFiles/file/vateradezavisabapa.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://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_off00010f7c.bin
fe9e4d5ef7efb208bd3e9f81e64e263b57ba9c794bf2fa6fdc22d8d2dea0f0f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F7C 10596 bytes
font_01_sfnt_off000127b9.bin
fbb89f52d6edc2c829b8eb6c33ade0404da17b311566d31f4313a03617cfb24b
pdf-font-stream PDF embedded font (sfnt) at offset 0x127B9 17792 bytes
font_02_sfnt_off00015664.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15664 16792 bytes