Malicious PDF — malware analysis report

Static analysis result for SHA-256 27491a238bbedc2b…

MALICIOUS

PDF

81.7 KB Created: 2021-08-24 00:27:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 45894bad9543058f205e31ca67cb9bcc SHA-1: 1013345e59dc6844e6934f390dab926c340d2504 SHA-256: 27491a238bbedc2b3761e9b6b174bf617cd3c7d97257dc9eb38a13c36262f548
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan distribution attempt. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable hosting, likely to redirect users to malicious content. The PDF's structure and embedded links suggest it's designed to lure users into clicking through to potentially harmful destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=aphasia+causes+and+types
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c004d1644a7---gusinorisewuxapal.pdf
    • http://vaness-sens.fr/ckfinder/userfiles/files/robogaxojujosudeja.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609bcc1094bd7---6067425434.pdf
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/0f40cea5751ff087e099b943064029c3/tasizejok.pdf
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/12121387079.pdf
    • http://doctour.hu/uploads/ckfinder/userfiles/files/45720136084.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b70c4536817---71683783056.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612178ad1a3f6---2985770774.pdf
    • http://www.gamylai.vn/uploads/files/suwedobofijawedonazireb.pdf
    • http://china-engine.net/ckfinder/userfiles/files/49665898901.pdf
    • http://ibtaker.ps/userfiles/file/84808526771.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607013e23b1b1---91466109853.pdf
    • http://firmykominkowe.pl/Obrazki/edytor/file/puvetizosadapemajufugij.pdf
    • https://sbsoftware.ro/admin/userfiles/file/85034495447.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160a70eb2cb966---zajexive.pdf
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abbbb54939b---jofiwa.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a500a8e8cad---dumunijonuvopijavaxesaju.pdf
    • http://ambvetfanini.eu/userfiles/files/wuteno.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16080e2c5c1238---66397970813.pdf
    • http://iworking.vn/uploads/files/41298326248.pdf
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c28caf22dc4---49707449125.pdf
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/bb6uuun7laft70sr86envukh1u/juxopupikane.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/c465ac4cc43fbd43aef0d7c8f67c99f1/bewop.pdf
    • http://hanasushimenifee.com/uploads/files/9521340357.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_off0000dcd8.bin
6840433146494231cd11151fb6134c472816dadb44e97b146071734d74b93e64
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD8 10540 bytes
font_01_sfnt_off0000f4e6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E6 16792 bytes
font_02_sfnt_off00010cf8.bin
1d1e58b859395c7cfb78e93d75e5bb409175bbc21427fc6b006f1d65a7b91c05
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF8 16868 bytes