Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4ace9f320a82c1…

MALICIOUS

PDF

82.1 KB Created: 2021-09-23 04:58:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1f60c187dd5d79b5d4ce5bb6dcc84952 SHA-1: 4afd257022af362580848357a12b3d319d36310c SHA-256: 8d4ace9f320a82c1772ff0a3d8faf25ce1609d874f3d1a940a9bc7f1517aad0c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF sample was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://orthopaede4you.de/userfiles/file/95117771216.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ec6925253---bunizinetumadopipo.pdf
    • https://fcksa.com/ckfinder/userfiles/files/sikazixosusomijozojozixux.pdf
    • http://locke-3c.tw/uploads/files/202109091434431718.pdf
    • http://tongdingjixie.com/d/files/21610551585.pdf
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fff817a86e---7713938822.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614b53cabbea1---46257082068.pdf
    • http://symbioticlifetech.org/attfile/fckimg/file///20210912212540_785004038.pdf
    • https://liantoong.com/archive/upload/files/63022415495.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139cc0e56942---sedobawafogix.pdf
    • http://jiangsutravel.kr/userfiles/files/20210921_051139.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/998fb467276b67c85e87a42eb4ac2107/15706822540.pdf
    • https://afayl.com/userfiles/file/retaremorunibex.pdf
    • http://woodbridgeabw.com/uploads/files/47611139536.pdf
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142629d79556---vofule.pdf
    • https://htchninc.com/d/files/lexib.pdf
    • http://kor-ra.ru/UserFiles/file/86033216569.pdf
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613214016d63d---4658912070.pdf
    • http://forumts.com/ckfinder/userfiles/files/70467754631.pdf
    • http://oishisushigd.com/uploads/files/44124037659.pdf
    • http://td-mg.ru/uploads/files/71866522937.pdf
    • http://www.hgbehringer.de/img/files/files/duxuwutiwinutudebig.pdf
    • http://vpecargo.com/userfiles/file/modosugafuforidedalewetid.pdf
    • https://moderator.lt/components/com_mijoshop/opencart/image/data/files/68335548490.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=creepshow+comic+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_off0000dcae.bin
b3cc6213175ddde073ba1fda390a7bd1ff5a286bbdedc54960ddffc96ff33d25
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAE 17620 bytes
font_01_sfnt_off00010a71.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A71 16792 bytes
font_02_sfnt_off00012288.bin
c8b1d40121d529041fc7dbe4321b4ee0328878ed196bba6c80a614e3ce5cf8a5
pdf-font-stream PDF embedded font (sfnt) at offset 0x12288 10592 bytes