Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd3ab3f56175d7ab…

MALICIOUS

PDF

70.9 KB Created: 2021-10-02 11:09:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4f5ea8d19494036e01e8a07224c4d554 SHA-1: 9948cc685e291de29b516ad5382c38cf7dba08ec SHA-256: bd3ab3f56175d7ab0cef26252125ee079bdc486024cba7e113fef7b9b0242358
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL patterns suggest a phishing or malware distribution attempt.

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 https://medvor.ru/uplcv?utm_term=recent+general+writing+task+2
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/3b0096f03c89e6b27ace50b182bbe633/93926168525.pdf
    • http://eaupureinternational.com/userfiles/file/womesimerigox.pdf
    • http://jingkangchem.com/upload/files/pokunekelugok.pdf
    • https://siriusdynamics.com/assets/uploads/files/75263805075.pdf
    • http://locthanhroyal.com/upload/files/79699689948.pdf
    • https://7mark3t2-7aya.com/contents/files/72145712313.pdf
    • http://winkeleninzundert.nl/uploadimages/files/81773835058.pdf
    • http://csc028.com/userfiles/file/20210929164807_chu8ya.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/gnkst0utcqf141a3fg0ujg2d3u/teribinusagatiwijet.pdf
    • http://fuguchair.com/upfolder/e/files/20210920204437.pdf
    • https://gyn-koe70.de/obrazky/file/kamufutarewotujevelele.pdf
    • http://dip.natura2000.pl/imgturysta/files/fixifekujudabifusisufa.pdf
    • https://simorgh.it/uploads/file/mekulewotuwazunixagonero.pdf
    • http://morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6afb4ba1a---fifetorejokakik.pdf
    • https://marathonblainville.com/userfiles/files/fegakapufabuwovowafu.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146573d5ba02---fokoxisatirazatexiligeku.pdf
    • http://medwin.kr/userData/board/file/85154866912.pdf
    • https://garraldaarquitectura.com/garralda_userfiles/files/didito.pdf
    • http://nirmalapublicschoolerumely.com/userfiles/file/93751583738.pdf
    • http://rafaelokazakov.com/file/xigevemufefekiwefaro.pdf
    • http://malopolskiszlakwinny.pl/upload/File/leziwewebedawowanak.pdf
    • https://lalicorne-hotel.com/userfiles/file/bigidalovovimi.pdf
    • http://austral-immo.com/userfiles/files/52199560905.pdf
    • http://gordostcrista.ru/userfiles/file/luninememino.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_off0000b291.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB291 16792 bytes
font_01_sfnt_off0000caa8.bin
4e63ec0b1c6dc06a05a1cd99aa508c47babd9391b93e550a0ac5de032cc92a07
pdf-font-stream PDF embedded font (sfnt) at offset 0xCAA8 10628 bytes
font_02_sfnt_off0000e338.bin
07b36a19585afd40c9c3d39019f054f72e95cd89fe634092ee3798841befc569
pdf-font-stream PDF embedded font (sfnt) at offset 0xE338 16976 bytes