Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe1a85221f6e4939…

MALICIOUS

PDF

76.2 KB Created: 2021-09-15 14:59:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7f122d61d4b5f671b7738bb57e7f5a67 SHA-1: 705a99306d0009caf1c476dc3caa5d62b08cabc0 SHA-256: fe1a85221f6e4939ecd27b8d524d443b157dccce9525d506c13a1af4529cd88a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. While no scripts were explicitly extracted, the PDF structure and numerous URLs suggest it's a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://laborke.ru/uplcv?utm_term=adb+usb+debugging+mode+enabler
    • http://dongphat.net/upload/files/saxunuru.pdf
    • http://lixupeng.com/uploads/files/ragunizego.pdf
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/bipupixawile.pdf
    • https://premium-house.uz/images/file/53137680114.pdf
    • http://geologicatoscana.eu/userfiles/files/27035975065.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16131403c28017---53986326102.pdf
    • http://mega.kz/media/upload/files/gakagisajovalexer.pdf
    • http://gopherandsquirrelcontrol.com/admin/images/file/61223395144.pdf
    • https://huanghecables.com/d/files/80481562834.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/c38d2befd00eb0577042811e8a8acb8c/67961650571.pdf
    • http://smolensk-bakaleya.ru/userfiles/file/madesozupepadilemupavad.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612efb8f68177---wafodifora.pdf
    • http://studiostocchi.eu/userfiles/files/73145787721.pdf
    • http://wonikquartz.com/upload/editor/file/1631427936.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/duo8fibq3kcracqt4chpc693i5/21266577978.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161414d8952771---dusupikakixitomapuduxivat.pdf
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/dac6d3837146485ba0e4f91cf8bd63f0/dokufipepapok.pdf
    • https://vcvscr.cz/www/www/fckphotos/file/mumowotu.pdf
    • https://tims.ro/ckfinder/userfiles/files/17407247904.pdf
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/30702894969.pdf
    • https://safecampus.in/cmsCart/upload/file/sodizewedudejumawidotam.pdf
    • https://kp-bs.ru/upload/files/zizuvaru.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/aced298548a43e4c8653213437b2fda1/56909745922.pdf
    • http://www.hkrns.org.hk/ckfinder/userfiles/files/41641861820.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/50d7a04cc51022349af6dbf968c1d33d/85871383324.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_off0000c712.bin
9ab64a94651a861e64aec5a658956300116fe58a77f27fe6867e65816252b8d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xC712 10716 bytes
font_01_sfnt_off0000df58.bin
15bd3e007d777d72ca70cebab4478858342943a4f847eb9ba071bade2e93d096
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF58 16904 bytes
font_02_sfnt_off00010b08.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B08 16792 bytes