Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7ad5b253b60fa0f…

MALICIOUS

PDF

88.3 KB Created: 2021-09-04 11:02:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c79760e8525dac9c48778b52840834d1 SHA-1: 9dc1e5254139f7e26fc9a76fe270a5bf5e2df01f SHA-256: a7ad5b253b60fa0f53a30e64e3b32e2713e285f211f3a3b3771b5929bf7569bf
232 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript and numerous links, many of which point to compromised WordPress upload storage or disposable hosting, suggesting a link farm designed to distribute malware. The critical heuristic 'SE_SECRET_RECOVERY_LURE' indicates the document attempts to trick users into revealing sensitive recovery information, likely to facilitate account takeover after a payload is downloaded. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 9

  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ambvetfanini.eu/userfiles/files/68847529763.pdf
    • https://reha.bg/content/upload/file/73964488840.pdf
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/01594ccb4caa15bf59bded72e150784d/16848822492.pdf
    • http://kaizousha.com/js/upload/files/topuvikedu.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160829a2505f1d---75007717554.pdf
    • http://euroear.eu/ckfinder/userfiles/files/sadudexusefuberirexobosa.pdf
    • http://mazdooradda.com/userfiles/file/zezibiduratifukebevijej.pdf
    • http://bigband-ulm.de/userfiles/files/2198019940.pdf
    • http://servicedental.it/userfiles/files/40182185939.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b99e35a16c8---38444718227.pdf
    • http://policylic.com/uploads/files/ruwiposumakogivuzevader.pdf
    • http://ersenergy.com/UserFiles/file/78062591088.pdf
    • http://naturallabs.fr/userfiles/file/zemipiditi.pdf
    • https://alutat.com/data/file/98951447416.pdf
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb85fc11c49---lawuvov.pdf
    • http://thunderstar.cn/userfiles/file/20210727063255584702495.pdf
    • http://air-ned.com/uploads/files/finimutosiriji.pdf
    • http://banghetretunhien.com/media/ftp/file/negulaxa.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/a111e42b46b30de2d94c9180fc57bd00/30655975634.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b03e8a88e8c---15989263831.pdf
    • https://skinrepublic.vn/webroot/img/files/68544020757.pdf
    • http://kechengchem.com/upload/files/77716392009.pdf
    • http://tvoirostov.ru/ckfinder/userfiles/files/vojigopofubelire.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=iot+agriculture+projects+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_off0000f1f3.bin
e637d8a06d7ff74b8f4dbceeadcee8336e42fcb996f720f6ab6021ceead18cc4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F3 18680 bytes
font_01_sfnt_off000122d7.bin
f56c06ff611083e0db2c079382b35a2f3c82cb7b3782f0270a87e5eddcca2d28
pdf-font-stream PDF embedded font (sfnt) at offset 0x122D7 10872 bytes
font_02_sfnt_off00013be4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BE4 16792 bytes