Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a5bb2d3df8012af…

MALICIOUS

PDF

81.8 KB Created: 2021-08-18 17:33:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b46add78f437eb962fa2047e8d25d4f SHA-1: e85e389ed944707cee81c25299aa93c03d2e0ac1 SHA-256: 4a5bb2d3df8012af96b87a2788bdf1a9716443140b5e50bd2c76c2e8b87ec2e8
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to multiple compromised websites, suggesting an attempt to redirect users to malicious content. The presence of external URIs and link farms indicates a likely phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ac90a6cb6---33277648360.pdf
    • http://stallingreunion.com/clients/a/a3/a37dbb3dca22f8cb40f44de83fe48269/File/42479436204.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/474970d84f7c34f79153367241f7ca12/sizorufeg.pdf
    • http://edwardlankin.com/clients/86087/File/serobujufokega.pdf
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/230976cc23f874258bc75f6188d88786/fubufujidowanuduto.pdf
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/b6aba9fea74cdce6c1342dcaf1f19646/27778741551.pdf
    • http://tvoirostov.ru/ckfinder/userfiles/files/24180135657.pdf
    • http://reelproductionshd.com/userfiles/file/wuvepesofu.pdf
    • http://quiltingacademy.com/fckeditor/userfiles/file/logiwomewamuwivilamu.pdf
    • https://marblobathware.ph/app/webroot/img/files/zojojunakar.pdf
    • http://stringladies.cz/userfiles/zenixed.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607bfc30a8adf---magazipapogoki.pdf
    • http://dansensvenner.dk/imagesfile///sutirufomozipoga.pdf
    • http://hanlacsclub.com/ckupload/files/tizegalukotaxufowuguwim.pdf
    • http://phillipsbrothersmill.com/clients/6/65/65192871cce8a6e36080a9ebd2808b02/File/97386983566.pdf
    • http://banhangcongnghe.com/upload/FCK/file/zalamedexotepudoladef.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac47aa4b95---wujufutofisezoseduxo.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609020791bd1a---pirewadepifumulaba.pdf
    • http://szao-spb.ru/images/news/file/rusavuzawomojesufujaz.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c46780201b3---66282149380.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/mfkoek2cva03aqonp267ob58bs/26233202072.pdf
    • http://japan-railpass.info/images/blog//file/24279154271.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=zor+ebob+ekok+problemleri+8.s%C4%B1n%C4%B1f+pdf
    • 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_off0000de5b.bin
557c7fb20f246fc6f217da6c19c20fdde75252eb757048a180d53f58805d4b37
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE5B 18720 bytes
font_01_sfnt_off00010c99.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C99 16792 bytes
font_02_sfnt_off000124b0.bin
52c1f5338266399cd61dd28003c7711df0f746e87c9d794dd14a5940b94ffec2
pdf-font-stream PDF embedded font (sfnt) at offset 0x124B0 10912 bytes