Malicious PDF — malware analysis report

Static analysis result for SHA-256 9871cf28b69979cf…

MALICIOUS

PDF

102.3 KB Created: 2021-07-03 01:01:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 70b537667ca2153c6dc3394e09c2225d SHA-1: ca193c0fa08483dcdc70bb8c85df51a736612d6a SHA-256: 9871cf28b69979cfab104c42f885b8a7e4d22a9fae7baee50e1dcabbf2abe33a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing campaigns. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious document used as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9887

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 https://archism.ru/uplcv?utm_term=tuition+fees+meaning
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/631b56eb2475d97b256bb33e9289b104/xolak.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/973ede603a199acd15c70216b9d67dcb/95070665890.pdf
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/86360c4a09c12f0f50f91625ef64ca71/noxerumimigajuwok.pdf
    • http://stalmost.pl/userfiles/file/xojedukisamenut.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/0778a9904a46df6f934ae87f878fc359/muvasuvukijede.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b967906b9b8---zobekukumup.pdf
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d607ff61d2c---17803755049.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b7161270247---81131626537.pdf
    • https://marigabung.com/contents//files/lijum.pdf
    • http://texmet.pl/userimages/file/dupinovudasuvikolumi.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/1126e8d54cde3e8811d0dd174cf7be93/55009496614.pdf
    • https://tavio.ru/files/file/41584411358.pdf
    • https://deltaguvenlik.net/userfiles/file/37894256122.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608576e00e3dc---46329925087.pdf
    • http://meruzhankhachatryan.com/app/webroot/files/file/83249275603.pdf
    • http://kulturazebrak.cz/userfiles/janomibumipad.pdf
    • http://digifast.cz/userfiles/pazifuxubosawom.pdf
    • http://cartonwrappingmachine.com/userfiles/file/norikobuvoti.pdf
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609862cd38d7b---wawatabatufevurujejabez.pdf
    • http://straub-online.ch/userfiles/files/mefuko.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c28f5571eb7f582b97300b6c9a291bee/wegokizipim.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5ca0b1e691d7c97b773d929f1011a260/vifupa.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16090e61e600e4---zimemisasanirevax.pdf
    • https://mvservice.it/file/37687938086.pdf
    • http://s292376414.onlinehome.fr/datas/imgmail/file/39201475621.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off0000f2b9.bin
09e18ff978d4f338a864ec756e8ff594bf6a8047452e03414f8a2e3c8a5f3c13
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF2B9 29640 bytes
font_01_sfnt_off0001291e.bin
afa45678986dbadcac5ba2cece3a0c3e7bbd141a1d1beeff26fdb7afe3b52618
pdf-font-stream PDF embedded font (sfnt) at offset 0x1291E 19864 bytes
font_02_sfnt_off00015b9f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15B9F 16792 bytes
font_03_sfnt_off000173b6.bin
9ae3060b5b4041ff17347649c54a22478c28c7ab2a7f4fe7bbc2dfab70288945
pdf-font-stream PDF embedded font (sfnt) at offset 0x173B6 10476 bytes