Malicious PDF — malware analysis report

Static analysis result for SHA-256 98bdff1dde420c94…

MALICIOUS

PDF

81.9 KB Created: 2021-09-13 06:52:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e17ca13bb528042f0a78f80be1563fc9 SHA-1: 4a58740dcb1cd85dbb8485e997dcb89fcdbfa96f SHA-256: 98bdff1dde420c94f2287121305563b3675a173ffcd7c2d914e1b2866a093621
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting. Heuristics indicate it functions as a link farm, with a high ML classifier score and ClamAV detection confirming its malicious nature. The primary attack pattern involves luring users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://stacjaregeneracja.pl/userfiles/file/leratorikaraw.pdf
    • http://lukinserv.hu/file/91922309973.pdf
    • http://podwierzba.eu/ckfinder/userfiles/files/68082429661.pdf
    • http://fthyhs.com/resource/docContentImg/file/2021-09-09/064c0fd39846bd9a21075101ceec9f24.pdf
    • http://aroma-es.red/yamituki-n/uploads/files/13535198469.pdf
    • http://lmalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71102797629.pdf
    • http://af.ssla.ru/images/fornews/files/17347712226.pdf
    • http://emblem4home.com/UserFiles/Member/File/12969710344.pdf
    • http://studioarchoggianiepartners.it/userfiles/files/lezopetujukebalubij.pdf
    • http://www.childofafrica.org/media/userfiles/file/sivazo.pdf
    • http://moscreen.in/cmsfiles/file/39761063064.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161340ed35a277---97962762687.pdf
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/82914512758.pdf
    • http://xn--80akoseq9f.xn--p1ai/userfiles/file/kovud.pdf
    • https://www.zochrot.org/ckfinder/userfiles/files/70533238543.pdf
    • http://olimpic.hu/ckfinder/userfiles/files/3746649272.pdf
    • http://agisma.ru/files/pages/files/tefabude.pdf
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff92d6c77f---32608418966.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8e7a84213---68259141254.pdf
    • https://menokatea.in/ckfinder/userfiles/files/vanivezagipevedilaj.pdf
    • http://pedraferro.com/files/files/11046149376.pdf
    • http://baoveantam.org/upload/files/61792213063.pdf
    • http://msslink.ru/userfiles/files/53147094666.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=tune+up+android+tablet
    • 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_off0000daf0.bin
82e2983887a9abf0d585bf5e2955077109e239bf22c5a558743a81447d0a050d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF0 18452 bytes
font_01_sfnt_off00010af3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF3 16792 bytes
font_02_sfnt_off0001230a.bin
2c4877c20d4834198ae54066014bb14b89d416a7acf797c1a71df5e7f9f77d14
pdf-font-stream PDF embedded font (sfnt) at offset 0x1230A 10420 bytes