Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b994cb1af1083e8…

MALICIOUS

PDF

79.0 KB Created: 2021-09-14 13:47:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 761d153c99a9339e6f911f94f6defed6 SHA-1: c979fab6113c9726e9a8f7c62a70e8dd0c3b870a SHA-256: 2b994cb1af1083e8d7e039a81f8ff016f7955f9328f7e38b2bf97ae3f239a42b
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially malicious or disposable domains. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oishisushigd.com/uploads/files/33442049087.pdf In PDF document text
    • http://ozhelalikram.de/resimler/files/pezod.pdfIn PDF document text
    • https://pagodatalk.com/_UploadFile/Images/file/79550850599.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/7082379059.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/4059310044.pdfIn PDF document text
    • https://cemb.ca/upload/editor/file/nutazoginofufevose.pdfIn PDF document text
    • http://erh-hu.com/userfiles/file/namigeniduziligixujosed.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161405a6bbb8e7---31709277286.pdfIn PDF document text
    • http://lechioutdoor.com/userfiles/file/91492797416.pdfIn PDF document text
    • http://soupworld.de/upload/file/28239844923.pdfIn PDF document text
    • http://trungnguyenjsc.vn/uploads/image/files/42343300353.pdfIn PDF document text
    • https://kidneystonetreatment.in/userfiles/files/22497013241.pdfIn PDF document text
    • http://mayepnuocmia.vn/data/ckfinder/files/21080726022.pdfIn PDF document text
    • http://bosch-elektronarzedzia.pl/catalog/file/19015238509.pdfIn PDF document text
    • https://parlagame.net/calisma2/files/uploads/serenuvovezunavijala.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/33511929493.pdfIn PDF document text
    • http://mcrlclient.gilcom.ro/ckfinder/userfiles/files/sitibezegeta.pdfIn PDF document text
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/vagaletej.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/lareresisobow.pdfIn PDF document text
    • https://bselink.com/userfiles/file/wewuze.pdfIn PDF document text
    • http://hasdeu.md/data/userfiles/files/motunonirinidu.pdfIn PDF document text
    • http://mxagproducts.com/upload/browse/file/zafidurorol.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/mexefepasagukigo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+increase+android+internet+speedPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD318 17076 bytes
SHA-256: cd0aa2bba655a107d84f0d79e3292848c83f565ab129c4b667327c83dd66e670
font_01_sfnt_off0000fe96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116AD 10536 bytes
SHA-256: 67127a568a29ea855b9e47e04758d16a7de4ded44c0c7a8de565bc4ba4174ef6