Malicious PDF — malware analysis report

Static analysis result for SHA-256 c102379ac7a2b344…

MALICIOUS

PDF

85.4 KB Created: 2021-07-09 13:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a2992fde4868ba399c3c291ab7d4ccc SHA-1: 85ad764369c6b2b0df38a8f1996e6a457e04aefd SHA-256: c102379ac7a2b344b198c2735613969c4c162b46a1697e95c2cfb221c9a44fc1
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to potentially compromised or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the link farm heuristic is sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://31kouqiang.com/userfiles/file/1624134164.pdf
    • http://bazis-expertiza.ru/ckfinder/core/connector/php/files/volizadujidozitodanipex.pdf
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/90ea3014a48bbffa7ef1a25c19253a84/17781374707.pdf
    • https://wotfiles.com/ckfinder/userfiles/files/16081686004.pdf
    • https://alshaabcoop.com/userfiles/file/kapewi.pdf
    • http://thaiboxes.com/piceditor/file/808507684.pdf
    • http://kutscher-customs.de/gfx/userfiles/files/8915981466.pdf
    • http://shortguycentral.com/ck_uploads/files/79425272397.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607798602f238---watox.pdf
    • https://gachbinhduong.com/upload/file/30996454032.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b019bda41f8---vaniselomibixafut.pdf
    • http://rolmech-strzelno.pl/Upload/file/fogasijawese.pdf
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abc3554b605---23289883675.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160826c9988217---29897274874.pdf
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/fd5398405a5476222d0de0298ec33e5c/tibexuku.pdf
    • http://emotionpicturesfestival.gr/userfiles/file/nokugosafikutikafefu.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160861e33a9ab0---68919405729.pdf
    • http://appletechsolutions.com/userfiles/file/jixowawovuwitet.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56f3c9c85e---76041357785.pdf
    • http://fkjz.cn/upload/files/2021/07/202107060351073933.pdf
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/2a03d1725169083734b1c0385c354aac/51315449343.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/3gugkg4lpb3v9cbddbnb14jv22/pabusig.pdf
    • http://apexibd.com/uploads/fck_uploads/file/vadanineniweguzufapapisep.pdf
    • http://djapm.com/userfiles/file/juluxuzobopilalidibeno.pdf
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/43bd205f4b0b38aed7814f0acaef2617/28888921396.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=react+native+input+component
    • 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_off0000ec38.bin
72bcef2f93b3f2772257f24abedc67cd9a84a621e5db229ab4a21a4d6f7c49a3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC38 10432 bytes
font_01_sfnt_off000103e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x103E2 16792 bytes
font_02_sfnt_off00011bf4.bin
5c05872f003a96984cfac1052df74490567a98df2b060b921a7604a600695fd5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF4 16892 bytes