Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fcaa036bb8e0082…

MALICIOUS

PDF

86.7 KB Created: 2021-09-09 20:33:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1176793e6967cacd6534661eb7d9da1 SHA-1: 427f9978cf60298841d073d04962a00395efb9d8 SHA-256: 4fcaa036bb8e0082e15558e8a5cdce45e2a382c3ea411bdb7031b21455c6ab06
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable domains, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://cyberbirddog.com/userfiles/files/99095875820.pdf
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/99314615806.pdf
    • http://ankaraeksioglu.com/resimler/files/pirigotulexororifi.pdf
    • http://motivationandmomentum.net/ci/userfiles/files/49728456993.pdf
    • http://madmojo.com/fckupload/file/33122542721.pdf
    • http://i-physiology.ru/upload/kuvome.pdf
    • http://kaztelcom.kz/ckfinder/userfiles/files/95469641088.pdf
    • https://atkarisuli.hu/userfiles/file/mimabilojukudegiforuzo.pdf
    • https://cityface.cz/res/file/33096280879.pdf
    • http://putzlappenborner.at/editor_up/85141391830.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320e67cd9a7---28453120560.pdf
    • https://dycmc.com/DATA/upload/files/202109020523159038.pdf
    • http://ibrahimalsada.com/pics/file/jodutasolomibepopaw.pdf
    • http://nujhimachal.in/img/uploads/files/63866571985.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b96fd8fce87701265127dd460a015b6c/jefosumexomogo.pdf
    • https://mimpidia2.com/contents/files/80833979970.pdf
    • http://av-jet.ru/userfiles/file/29639869445.pdf
    • http://kooijobs.in/ckfinder/userfiles/files/99319133084.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/3761abb65416395ca993fcc835fe09e2/kimebil.pdf
    • http://autosoftware.company/autoresponders_images/files/83269666099.pdf
    • https://ukmalayalamnews.com/userfiles/file/bifan.pdf
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jezedolotiwekunekulinade.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/esrlkrbbd4jr9oqu99cdj0277f/99821383446.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134db6ebb3ee---tobedes.pdf
    • https://nationalshield-uae.com/userfiles/files/rotigatezew.pdf
    • http://ch-bovi.com/upload/files/18805559107.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=pokemon+mystery+dungeon+green+rescue+team
    • 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_off0000e5e1.bin
7c4800261039630db1905b2d25b0820fdd01d63153273991f37f58c1870af326
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E1 10880 bytes
font_01_sfnt_off0000fee7.bin
3552fb18a0ff9cd4afedbc4ecf513ed1cf9829e56328525a1bab6861bd7380e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE7 20756 bytes
font_02_sfnt_off000134e3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134E3 16792 bytes