Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f1b3bbb937d4b8b…

MALICIOUS

PDF

79.0 KB Created: 2021-07-17 18:19:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b734384559dd973215d789b9ec5ebcea SHA-1: 105bb4ac35156b94cc1ef13a721e521787f5d28f SHA-256: 1f1b3bbb937d4b8b35f8733220bf5cb4dd0e209bf981ee0c1c1536565207c6c2
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the numerous external links are the primary indicators of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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.allterra.group/wp-content/plugins/super-forms/uploads/php/files/f8de25e2fdb4ad11f224f757dc2930f8/62640450390.pdf
    • http://naszymsladem.pl/upload/file/81934531252.pdf
    • https://mintedimages.com/ckfinder/userfiles/files/kakodavizatolaxavore.pdf
    • http://misosmile.com/upload/editor/files/33301085701.pdf
    • http://mjsolankifoundation.com/fck/imagesfile/40449991032.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/f62ee7577d3b2ba1b973ce42f4905acc/22128499158.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a60c40ed97---70123027768.pdf
    • http://iseveranscopy.com/upload/editor/file/zalojesisizojukakewevekis.pdf
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/4622907a4368c2eef53d17927abf9473/vuluvanuvu.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160858caca24c0---lirenapap.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609ea31d57a75---ruvenezolamapifi.pdf
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16084b04b221da---sedukikakemalot.pdf
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16080a112377b5---76578035660.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e7918ab5c---56322680592.pdf
    • http://emirates-offshore.com/uploads/image/file/wogazovopuviraru.pdf
    • https://kemxoi.vn/app/webroot/files/images/pages/files/denufuxediwodobax.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0abfe27889---36036066952.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/wofedarur.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16076e45e7ed47---bapeboxeroxofomefuj.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b850832f90c---vudowakekoja.pdf
    • http://aksaaydinlatma.com/img/editor/image/file/selogabuf.pdf
    • http://playbabydoll.com/userfiles/file/vuxali.pdf
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/6obfn2ht551upjja0a6e5q8t9i/16134093159.pdf
    • http://ehoron21.mn/uploads/files/xavileseliveresiluf.pdf
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/3551554d147c7ec645ad2b84c4630a88/zaxuje.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=torque+chart+for+metric+bolts+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_off0000d445.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD445 16792 bytes
font_01_sfnt_off0000ec57.bin
c1e04d9fcf90f499a51b33537c6882ce912eacbb91d487606d933ffba62dbe12
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC57 15880 bytes
font_02_sfnt_off00011545.bin
46008a760622c7090713553e53b9f9265b86d16b9dadac79aff05345855ca04c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11545 11132 bytes