Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c85bbc82ccf23e3…

MALICIOUS

PDF

105.1 KB Created: 2021-03-29 13:26:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 60999db4cc380372f963e5d2e874efde SHA-1: 07c03b38e4e6f872664b61e3423db72ff9c4bdbf SHA-256: 2c85bbc82ccf23e3585db3d78296c396a829d8cd5af2cf4dcc48cae211d98f1a
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, identified by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. One of these links, https://jumiwimov.ru/123?utm_term=skill+set+matrix+template, is flagged as unknown reputation. The ML classifier and ClamAV detection strongly indicate maliciousness, likely related to phishing or distributing further malware. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jumiwimov.ru/123?utm_term=skill+set+matrix+template PDF link annotation
    • https://nokajadum.weebly.com/uploads/1/3/4/8/134887388/nezexe.pdfIn PDF document text
    • https://sarisakela.weebly.com/uploads/1/3/5/3/135308925/pabikubuxe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500889/normal_5fc677b473149.pdfIn PDF document text
    • https://sitegevom.weebly.com/uploads/1/3/4/6/134664280/puziloz-gujetagixe-keloxezuwavufik.pdfIn PDF document text
    • https://pedexanagokol.weebly.com/uploads/1/3/4/6/134635549/fopakegepuxojiwomozi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477155/normal_5ff2705e74f97.pdfIn PDF document text
    • https://jabibodusap.weebly.com/uploads/1/3/2/6/132681053/80857b940.pdfIn PDF document text
    • https://kipunelikerave.weebly.com/uploads/1/3/0/9/130969086/rawinizeluk-gopadusekaz-vufafawuxok.pdfIn PDF document text
    • https://mamexobupelo.weebly.com/uploads/1/3/1/3/131383482/7587590.pdfIn PDF document text
    • https://gidafefutor.weebly.com/uploads/1/3/4/0/134040883/0120a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424951/normal_605a752e5dec6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468286/normal_602a7c616bc62.pdfIn PDF document text
    • https://doxuvufunufake.weebly.com/uploads/1/3/0/8/130874670/solumenawonu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/ffc0fa5d-e15c-41d0-b27a-6b8612b9909c/proform_exercise_bike_walmart.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/11ad32d0-bb85-433c-82d1-7bd0f1e041a4/307478255.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/172946b8-ded0-48b9-a3a4-7b75cf460381/dovelonexaj.pdfIn PDF document text
    • https://s3.amazonaws.com/ginutu/decoupage_sheets_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d54090a-9be4-4bac-ba4e-a09cc9045506/budumulu.pdfIn PDF document text
    • https://s3.amazonaws.com/gasodamuza/frys_first_100_words.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d201a383-b691-4bfd-af27-6ea9251765fb/70229349636.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/640eb862-3c61-4b10-9387-857f9cadb71f/zerokedituguva.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://scripts.sil.org/OFLIn 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_off0001473f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1473F 5200 bytes
SHA-256: 2c4738bf04bf2f8f4d89387c95e8c5b10ae09493b9d3b5cda3a9e9acc1ca2891
font_01_sfnt_off000158db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158DB 11640 bytes
SHA-256: db201118b784c271a735642ef04d529e89ced3ee193baa515547f8f37d76305f
font_02_sfnt_off00018084.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18084 16136 bytes
SHA-256: 2df60db25c4006ebf5ce7f30ca7461b7931ff48239c1caafece913cf4cb3b6f2