Malicious PDF — malware analysis report

Static analysis result for SHA-256 751f86b38b17d182…

MALICIOUS

PDF

90.8 KB Created: 2021-07-22 21:21:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 44eb8f448a33b26e5c3781ecd8370d29 SHA-1: 034be790c3b97e395b067d2e48a7e7f95d3291b9 SHA-256: 751f86b38b17d1822e8d58a81fd6326105c175b89879cb58ddc51db286a64d80
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting, likely to distribute further malicious content or phish for credentials. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://cungcapluonech.com/upload/files/visapuza.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/0ummrvl1ujvl4temdte1ih5p6a/22518306675.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160719e13f3a11---3621730188.pdf
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609b20bd77ef6---tazavetog.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df36e31c246---75595445218.pdf
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/4a3a03d6bcd30e332818b74be25031af/sekimugig.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/8ok36295279u7a2i4no7qosg95/26438728039.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/3dc2bdf91532f5dc9aa590c6d5160303/36869732690.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16084ef6f44322---xarejadinavoveduxusab.pdf
    • http://nessium.net/userfiles/file/xopoluje.pdf
    • http://jrpst.pl/userfiles/file/tulowulepaduv.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-5-1/20210501042643956986.pdf
    • http://valdhans.cz/userfiles/file/narigirinef.pdf
    • http://aotwresort.net/ckfinder/userfiles/files/kabekovuxikob.pdf
    • https://fortworthdental.net/cmsCart/upload/file/xixibumezof.pdf
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5b07c177b7---sekatupediforejidakosidat.pdf
    • http://akinmedikal.com/uploads/file/77216200136.pdf
    • http://www.findvoters.com/userfiles/file/87505410995.pdf
    • http://barrybusiness-crm.com/ressource/devis-photo/files/joxip.pdf
    • https://bluebeakbranding.com/wp-content/plugins/super-forms/uploads/php/files/f8558f87279a838a0abcd0befd3a3b35/28939980108.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084bbd3c90b0---66711414329.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=quad+strengthening+exercises+at+home
    • 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_off0000fef2.bin
a591c286d7fad1b6cd560b2ccb7440f4f28fdaa0930e8daf83c2936b993c8011
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF2 11032 bytes
font_01_sfnt_off00011857.bin
75ddee860d7ab42f75644f4b3020c545fe16027cafbca064b14ef6a5bda5605e
pdf-font-stream PDF embedded font (sfnt) at offset 0x11857 16792 bytes
font_02_sfnt_off000143aa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x143AA 16792 bytes