Malicious PDF — malware analysis report

Static analysis result for SHA-256 357104f93bb3d0c1…

MALICIOUS

PDF

77.1 KB Created: 2021-07-17 13:06:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2394f6b72913197abaf5fc30740ce3c8 SHA-1: 3c47f4cca2899454da551e7d0d4a394f03b22114 SHA-256: 357104f93bb3d0c16e070431997edd462130b991f864ecce606289603c8fef57
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm and by a ML classifier as malicious. It contains numerous URLs pointing to external websites, several of which are hosted on compromised WordPress installations or disposable domains. The ClamAV detection 'Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0' further supports its malicious nature, likely serving as a phishing lure or a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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 http://jngf.cn/files/file/8528160829.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075205f33fba---15445532954.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/nilkbqmf46go6gpmfb8gci0ifs/xajawimubetipini.pdf
    • http://buergerforum-tirol.at/file/9132147308.pdf
    • http://adamlegal.com/userfiles/file/zibelijerewin.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c591fb2fda---wuwidevuxe.pdf
    • http://adams-gold.ru/archive/image/file/wafokofugadod.pdf
    • https://monuments-msk.ru/wp-content/plugins/super-forms/uploads/php/files/1af5fe264d417aba3fd30295d5b7c301/87969967930.pdf
    • https://karapinarinsaat.net/userfiles/upload/file/40053042356.pdf
    • http://reutlinger.pl/userfiles/file/xarazegekaxura.pdf
    • http://rotang.net/userfiles/file/3467555786.pdf
    • http://arniestribu.com/campannas/file/61124761083.pdf
    • http://assushop.com/userfiles/assushop.com/file/lunebudaga.pdf
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607fbd6ed958c---letisidubufodokuvezuxo.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085325b3f63c---53475141545.pdf
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbcc9ff3da3---nolidozo.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9835258ba---2441824153.pdf
    • http://ahcxdq.com/uploads/file/311750559504.pdf
    • http://uni-farm.pl/ckfinder/userfiles/files/pafexud.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607614c066e69---40189558103.pdf
    • http://moveworldtogether.com/datas/files/nufoduzadajamapezofewetex.pdf
    • http://chinajessie.com/seadata/data/uploads/img/file/16249421960.pdf
    • http://albino-pitti.com/pub_img/file/tisolisokagujusogezupe.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=all+search+history
    • 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_off0000ce08.bin
fd1ed794ab1ec9e9febe35943d92ebac4ee0e5e351550d30dd11b11004000d8e
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE08 16256 bytes
font_01_sfnt_off0000f841.bin
e6ec40b73cb6f57c452ce265336b3a506aac6a84d25d4720faaa996692ff5b2d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF841 10320 bytes
font_02_sfnt_off00010fbe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FBE 16792 bytes