Malicious PDF — malware analysis report

Static analysis result for SHA-256 158d22ce7bd2c3d0…

MALICIOUS

PDF

97.7 KB Created: 2021-08-09 09:21:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: da02eb1e9904074ee6b997eee4310dc0 SHA-1: ee4d5b27eb744ce7c03650546fd9c2f1bd37e597 SHA-256: 158d22ce7bd2c3d050342517fa52b5e4c7ee077a76432bdf3667144cf2675a3b
176 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. The heuristics indicate it contains a link farm pointing to compromised WordPress sites and a callback phishing lure, suggesting it's designed to trick users into calling a fraudulent number. The document body is heavily obfuscated, but the presence of embedded URLs and the overall heuristic profile strongly suggest an attempt to exploit the user through social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://ketchas.ru/uplcv?utm_term=barron%27s+toeic+7th+edition+pdf+vk
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/d6nlin7thfa3igtjk9apoimu75/47893150178.pdf
    • https://www.letspassdriving.co.uk/wp-content/plugins/super-forms/uploads/php/files/ffrq2np82embr93tn578d1b5v4/bopivolobinalo.pdf
    • http://cs-web-design.de/ablage/userfiles/files/28335739478.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160802e5b69015---menujiwote.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/0ttn7ajum5v1p5p961aad928kg/ziluxiwedexoworapipoz.pdf
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/1d1ac2e19a4a9abfdb94f199830206f3/21125002732.pdf
    • http://wonderpanel.com/app/webroot/img/file/44206436439.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e01d85299---89510075956.pdf
    • https://lescourailleurs.com/upload/editor/file/xexajinopofiku.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609842677655d---nakuximoditobubugokifo.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ba44272fe---tipeviduxalonir.pdf
    • http://rajskiewakacje.pl/userfiles/file/sivukigesekoj.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16090bf0d93bd9---18955945599.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/60752688856.pdf
    • http://studioturina.com/userfiles/files/25256924236.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610d7e015f2ef---30714146563.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160fc0c8cc29b2---xuvovubuf.pdf
    • http://autoset66.ru/admin/ckfinder/userfiles/files/96660329682.pdf
    • http://u15.ch/ckfinder/userfiles/files/zomakarozomuresugeviki.pdf
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/f2586a2d7b6441a1deae15a98280b40a/xezenis.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/e601bc136a9ba9b35dbfdce45418f7b5/15885606735.pdf
    • http://flexa.cz/docs/file/40010523101.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/4e6a4902392e5ce6fd118ebc4a6d727b/92117383426.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609090e619098---punavipabomodipax.pdf
    • http://caycanhtuyhien.com/uploads/image/files/66627002233.pdf
    • http://noticiascgnews.com.br/ckfinder/userfiles/files/59019746684.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_off00010c16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C16 16792 bytes
font_01_sfnt_off0001242d.bin
beecf76876199c00faad3ffcd285b2f2a3b3b32455ef27117403f5c7974f7f90
pdf-font-stream PDF embedded font (sfnt) at offset 0x1242D 10968 bytes
font_02_sfnt_off00013dbb.bin
8da0eaebc0fbf63b76b3d8911a4bb81ecfc72693a76bc7e64a888bc8079d137c
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DBB 26376 bytes