Malicious PDF — malware analysis report

Static analysis result for SHA-256 c54ae39d612c5c4b…

MALICIOUS

PDF

83.3 KB Created: 2021-09-11 12:43:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6ee40c35e7e3a18cdd5c4c043144960d SHA-1: 00238aa2975e25e462498c0e86cc65ec09865b52 SHA-256: c54ae39d612c5c4bbda4c49137c7fdaeb5e6173a78f1286a5a382244c1d2a922
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document functions as a link farm, directing users to numerous external domains, many of which host PDF files. While no scripts were explicitly extracted, the presence of external URIs and the link farm behavior strongly suggest a phishing or malware distribution vector, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://ulsantour.com/FileData/ckfinder/files/20210902_A81D4EC248D21C3C.pdf In PDF document text
    • https://absoluteanytime.com/media_file/files/files/49115512676.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/88712421086.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/xijerisololiroluf.pdfIn PDF document text
    • http://pi-consulting.ch/download/zipareru.pdfIn PDF document text
    • http://peter-crooks.com/userfiles/file/pejitipunolifogemetizi.pdfIn PDF document text
    • http://recviem.ru/img/upload/tawigarikuwujedoseniximom.pdfIn PDF document text
    • https://investincarpathians.eu/app/webroot/media/files/50405572275.pdfIn PDF document text
    • http://bijverhoeven.nl/uploads/files/buguratumo.pdfIn PDF document text
    • http://spbmedaks.ru/sites/default/files/uploads/13428923283.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/33462822395.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16138588ce96e7---80084877187.pdfIn PDF document text
    • http://addon-colsman.somantec.net/ckfinder/userfiles/files/togap.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/75563748352.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161302e1019b23---zobokijikafebow.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/vomiminafejebololuzaw.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/4377197672.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/pifutitozimibivup.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///zelololasidalobajere.pdfIn PDF document text
    • https://xn--b8qxb801j.tw/upload/files/fozijobeguduwadipezufi.pdfIn PDF document text
    • https://seikai.jp/free_images/files/jufesuwovefunuxar.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/metikoronan.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/87365848231.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=roblox+home+1PDF 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_off0000e1b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B1 9988 bytes
SHA-256: 74da577f268e88e36ebdeeca407dcab0decba2999f342dae29c859932036e961
font_01_sfnt_off0000f7d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7D8 18272 bytes
SHA-256: 972661ad4c4697c690f378f5d931be898dc25bdd36c23aee0cd979543ceef83e
font_02_sfnt_off0001279e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1279E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1