Malicious PDF — malware analysis report

Static analysis result for SHA-256 3809cb69d6d101de…

MALICIOUS

PDF

86.1 KB Created: 2021-09-10 17:51:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1783c59b01bfdf40c16e01e6d1f9a105 SHA-1: 30ebe972b11babae6f75fb6ca48481c7144aa7b3 SHA-256: 3809cb69d6d101de43725ae77c791f0038d860eff92460c99611d356b0e489af
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133bd1458372---ditivepegoviw.pdf
    • http://trunglamdecor.com/uploads/userfiles/file/29979491348.pdf
    • http://studiodrago.eu/userfiles/files/35213296875.pdf
    • http://dailymaydemtien.com/userfiles/files/dunabaneg.pdf
    • http://rfinshaat.az/userfiles/file/55268000500.pdf
    • https://cplastik.cz/data/cms/file/92713944551.pdf
    • https://ibrahimkoc.com/images/Media/files/69662451823.pdf
    • http://hbtsap.com/Upfiles/news/file///xujuj.pdf
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/74703486151.pdf
    • http://hotel-gerard-dalsace.com/upload/document/34058368399.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/16014fd960330d6c842ee8f2734433f1/54082786708.pdf
    • http://ty-universe.com/image/files/20210909_191425.pdf
    • http://nktrading.qa/file/files/foziwekipijuvo.pdf
    • http://www.tecnologycenter.com/admin/uploaded/fck/file/lamovosepilimix.pdf
    • http://stmrcstvm.com/userfiles/file/gobugibixubinaguzume.pdf
    • http://fsoa.cn/userfiles/file/21301192766.pdf
    • http://beiwendq.com/data/attachment/file/12040486359.pdf
    • http://skolky.info/foto/images/file/59278947945.pdf
    • http://haitrungkim.vn/uploads/userfiles/file/89200552179.pdf
    • http://paglialonga.it/userfiles/files/57916402423.pdf
    • http://restaurant-lyons.fr/userfiles/file/zigewagigateri.pdf
    • http://lecostationery.com/files/file/jaxuwovisasemin.pdf
    • http://dietaltop.com/userfiles/files/94980760363.pdf
    • http://appextskihjthj.handysociality.com/upload/files/jivuvususawenusaza.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c37f8c32e---35384689279.pdf
    • http://shengnabei.com/uploadfile/file///2021090411000038.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=voice+changer+for+ml+gaming
    • 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_off0000ea0e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0E 16792 bytes
font_01_sfnt_off00010220.bin
abc47901c4db169848398d5cee5122e8a1dae467ce68c9e3df91b0a9647c1473
pdf-font-stream PDF embedded font (sfnt) at offset 0x10220 18740 bytes
font_02_sfnt_off000132dd.bin
adc521d45a1be697eb97474ac560623743445879221f22948a1c1c816607c8c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x132DD 10484 bytes