Malicious PDF — malware analysis report

Static analysis result for SHA-256 d99a523e0c9492a8…

MALICIOUS

PDF

67.7 KB Created: 2021-09-10 11:21:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 35e30a2b4a2885a352f80e8f6171d59c SHA-1: 58461eb07297dd43d18fda3a4230ca429d738979 SHA-256: d99a523e0c9492a8288dbef8627f5a7263dc2474717b37da14e35081976c854e
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a single image designed as a lure, with a clickable link that directs users to external URLs. Heuristics indicate these links are often part of phishing campaigns or lead to further malware. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for credential harvesting or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://hillsdalehorseboarding.com/ckfinder/userfiles/files/pawosilujaxukosoxoji.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161393f02dc640---nesimokapajitap.pdf
    • http://dotacjedlaoze.pl/userfiles/file/50574953728.pdf
    • https://plasy.com/uploads/file/tefubirenakeb.pdf
    • http://market-oborudovanie.ru/upload/file/61054656393.pdf
    • http://www.prieteniitehnicii.ro/documente/file/493599045.pdf
    • http://farmina.ru/uploads/files/zukavukagogedadip.pdf
    • http://artsar.pl/userfiles/file/xasokafazizux.pdf
    • https://childrencareandliteracysociety.org/userfiles/files/jojogox.pdf
    • https://krassimirtaskov.com/userfiles/files/pitixaxarosokoguxez.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/767652915f59151018fdf4ad0c6be63a/goreradubenijovufotejuga.pdf
    • http://lobanowscy.pl/userfiles/file/71933438936.pdf
    • http://daejonggyoyc.com/userfiles/file/20210904065516.pdf
    • http://cecev.com/stockages/files/sulowexonuwawepuwizanover.pdf
    • https://lapakunited.com/contents/files/rimaxurenaveresoxuro.pdf
    • https://partetesal.ir/data/file/badaren.pdf
    • https://cambodiaangkorhomestay.com/userfiles/file/23983877174.pdf
    • http://isdoor.ru/uploads/files/9219124692.pdf
    • https://fishuntpesca.it/file/wowusa.pdf
    • http://neoneofitou.com/ckfinder/userfiles/files/10334552979.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/161316d7e63278---wazewiregopagetonidep.pdf
    • http://www.civilhospitalpalampur.in/img/uploads/files/27804846114.pdf
    • http://metallpress.ru/files/xuzukat.pdf
    • https://i-intelli.com/ckfinder/userfiles/files/3601846322.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=best+player+for+smart+tv
    • 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_off0000ae4b.bin
e12d6e6bdecfe6df00eedee5f4b640962e92f52ab264b292ec0a6b32ffd13d12
pdf-font-stream PDF embedded font (sfnt) at offset 0xAE4B 14060 bytes
font_01_sfnt_off0000d12c.bin
b82f7659d560599da9a586b62a4a8c40bdbdb6ccca2a1b78e9c06f54227a0439
pdf-font-stream PDF embedded font (sfnt) at offset 0xD12C 10556 bytes
font_02_sfnt_off0000e971.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE971 16792 bytes