Malicious PDF — malware analysis report

Static analysis result for SHA-256 b173b4f79af636f2…

MALICIOUS

PDF

84.1 KB Created: 2021-09-09 08:56:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7cbed461538deef3bf87efa46574b0d7 SHA-1: 06458d1ebcb8eda2a79ae64c33c37d6fd6d4124a SHA-256: b173b4f79af636f25ff3b0e90d991f3d27a86f3ce47634ca258cf88afc07839e
164 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and other disposable hosting sites, suggesting an attempt to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of a 'download button' heuristic further supports the lure mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://unstitchedfootwear.net/files/file/4837901150.pdf
    • http://doggystylzgrooming.com/admin/photos/file/nagalarapupafogakunuf.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/7a9131fdd7b435d82195aa51f0fee59b/nuzafuzoxomosigidukati.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/4f7817123050930686703dfaf042cf2b/14246986821.pdf
    • http://bebelino.ru/userfiles/file/31580695878.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/818d1e17e1c02b220bf245c4cbaa5fe5/2546487450.pdf
    • http://vimbark.sk/editor_uploads/files/98339948800.pdf
    • http://35ct1.com/images/ckImageFiles/files/41017543000.pdf
    • https://bnbtravels.com/ckfinder/userfiles/files/fevewida.pdf
    • http://www.advokat.com/app/webroot/img/fck/file/nedofaxosigobuvofipuzu.pdf
    • http://futureinfashion.com/ckfinder/userfiles/files/vutiz.pdf
    • http://benetworkingpro.com/ckfinder/userfiles/files/1792968852.pdf
    • http://duet-czluchow.pl/userfiles/file/55189047708.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16134b7e1db6b4---miwezaneturutidazuz.pdf
    • https://www.larche-de-jules.fr/ckfinder/userfiles/files/fesugomokegejafegozemem.pdf
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/839790069.pdf
    • http://thunderstar.cn/userfiles/file/20210906153754169320624.pdf
    • http://norrlandet.se/userfiles/file/28294710847.pdf
    • https://saksisan.com/upload/ckfinder/files/93276911812.pdf
    • http://king-pro.com/userfiles/files/jafuxoxenisis.pdf
    • http://qdsenfeng.com/data/files/86438251236.pdf
    • http://asesorgubernamental.com/images/file/nakopevana.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=god+of+war+ghost+of+sparta+ppsspp+android+cheats
    • https://www.posluh.hr/ckfinder/userfiles/files/zadovodirijelarokexovupo.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_off0000e18e.bin
62b13cb94f7cee709ede543fb89dbae77553478256545ab60c6e8454ff55f6ef
pdf-font-stream PDF embedded font (sfnt) at offset 0xE18E 18324 bytes
font_01_sfnt_off0001111f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1111F 16792 bytes
font_02_sfnt_off00012936.bin
0b6a2b136b2074ed14898e8ecb511ae2eef14f7e08be07440e8a0bb9cd68548c
pdf-font-stream PDF embedded font (sfnt) at offset 0x12936 10980 bytes