Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7f00441e96625c0…

MALICIOUS

PDF

74.2 KB Created: 2021-09-14 07:56:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 45b35d4f9a4a5ab76a7abf0548ec4ecd SHA-1: a55c48a2bf17da3aa3c0985d6b45d48eb636d619 SHA-256: a7f00441e96625c0cadcb83662563d7890b1b9668fd902ca0e4351b86b5cccfa
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, containing numerous external URIs pointing to various domains, many of which are likely disposable hosting. The document body is heavily obfuscated and does not provide direct clues to its intent, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://archism.ru/uplcv?utm_term=identifying+the+vertex+of+a+quadratic+function PDF link annotation
    • https://myarchitect.es/ckfinder/userfiles/files/48273318841.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/juvugupofugatezevuvasike.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/48573450391.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/bumenomuzulo.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/73ea3d2aafc471afec24f15843114314/soxejegatuga.pdfIn PDF document text
    • http://americasbestwingspa.iorderfoods.com/uploads/files/94135603121.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/23923630537.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/vabesanatok.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/61255755768.pdfIn PDF document text
    • http://nikacarpet.com/My_Project/Hamishe_bahar/ahar_img/files/43171501754.pdfIn PDF document text
    • https://congchunghadong.com/uploads/files/josejupuvunimeka.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/5f7e1401df307aca40249cb324a848ff/24361946251.pdfIn PDF document text
    • http://chrisdepanneservices.com/Sites/cds/files/xivudomuzelobogog.pdfIn PDF document text
    • http://rucodelniza.ru/userfiles/file/weris.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/wotuminozanelikezup.pdfIn PDF document text
    • https://www.db-ynox.fr/ckfinder/userfiles/files/780963927.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/35808785086.pdfIn PDF document text
    • http://xz-brand.com/ckfinder/userfiles/files/kutimumowonoruda.pdfIn PDF document text
    • https://investir-petroleo.pt/ckfinder/userfiles/files/porar.pdfIn PDF document text
    • http://ayrh.internet-match.com/upload/files/vetuligabofadakerezanotil.pdfIn PDF document text
    • http://maskaevlawyer.ru/userfiles/file/javopusimanize.pdfIn PDF document text
    • http://administratieindex.nl/images/uploads/jubasamiruwikiwapezixife.pdfIn PDF document text
    • 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_off0000bbef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBEF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD401 17752 bytes
SHA-256: 5dd2aa25f0e2fb9b93ff842578dcc61b57c00fe0f61380bfccb962dbdfe393e4
font_02_sfnt_off0001020f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1020F 11020 bytes
SHA-256: 93b4b142e4bacfa2f4d790f054952fd541d038878082baacc43ceaa372889eff