Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c8b4858409843b2…

MALICIOUS

PDF

79.6 KB Created: 2021-09-12 06:55:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0da0313ee5cf1ba78fa918ccd7524f43 SHA-1: 7a632ab7032501a92ff69a204eecbea80112f605 SHA-256: 0c8b4858409843b2072d4a8881ce550116939704eb565c017e5a6370d278ace0
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document is flagged as malicious by ML classifiers and ClamAV, and exhibits characteristics of a phishing lure. The document's content, though heavily obfuscated in the provided excerpt, is identified by heuristics as a 'Recovery secret / private key request', indicating a social engineering attempt to extract sensitive user credentials. Several URLs point to compromised CMS uploads and link farms, suggesting a distribution mechanism designed to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • 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-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://icrs-as.com/userfiles/file/kadasawaso.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613243f26816e---95903953750.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138427d95bb3---14947646151.pdf
    • http://twgo8.com/uploads/base/files/202109110444534406.pdf
    • https://sicurezzaips.it/uploads/file/sejazerojekesi.pdf
    • http://antifftech.com/uploadfile/file///2021090423194889.pdf
    • https://soechi.com/userfiles/file/wujeresema.pdf
    • http://www.yevres.fr/ckfinder/userfiles/files/16852065049.pdf
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/dabarufudavame.pdf
    • http://zl369.net/userfiles/file/saxivelevumixefafej.pdf
    • http://levotst.com/uploads/files/vuzotun.pdf
    • https://panelshock.com/userfiles/file/kevujadij.pdf
    • https://vinniescustoms.com/userfiles/files/86894307084.pdf
    • http://bayanairag.com/uploads/userfiles/files/31429094827.pdf
    • https://tcremich.lu/files/files/20437553066.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161372be19d18c---90403767360.pdf
    • https://fallsplat.se/bildbank/file/35428841273.pdf
    • http://stensoproject.com/userfiles/files/kejisadawejifotibor.pdf
    • http://pronobile.de/catalog/file/20044480328.pdf
    • http://mikol-styl.cz/userfiles/file/nibojimesubar.pdf
    • http://unitez.net/images/newtech/files/fezutov.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb7d82c9da---11868399570.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=ldplayer+download+mac
    • 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_off0000d356.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD356 16792 bytes
font_01_sfnt_off0000eb68.bin
61ef1b43489ec665f3089350c5b2e21e9d146645f951eee7275d611c880f28e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB68 17920 bytes
font_02_sfnt_off00011974.bin
0093a42863b9d7f3d44b827468e31a1ca13961268b523a2b57d7c64ff95e9b31
pdf-font-stream PDF embedded font (sfnt) at offset 0x11974 10472 bytes