Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa57c3990a887b06…

MALICIOUS

PDF

106.3 KB Created: 2021-03-20 20:31:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a8ead982aabab88055727db8bf753318 SHA-1: 236881e2b4909c2d87b86ee1da026c9f343072a4 SHA-256: aa57c3990a887b06a54dae6cb3d43afbb2187fa46bdf9971609c5aa6a4183ca2
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm on disposable hosting. The 'SE_CALLBACK_LURE' heuristic indicates the document is designed to trick users into calling a phone number, likely for a scam. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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/strik?utm_term=jazz+chord+progression+theory+pdf
    • https://kanevuto.weebly.com/uploads/1/3/4/4/134484588/4b1cc0c.pdf
    • https://likobikumenaf.weebly.com/uploads/1/3/5/9/135961418/bunetomi_wobupekaxo_sipupixekire.pdf
    • http://lipuwisapi.mywebcommunity.org/94274022184.pdf
    • http://nidewopovuwubo.mypressonline.com/27423510.pdf
    • http://kosonetibekub.medianewsonline.com/calendario_serie_a_tuttosport.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/pirosisob/career_paths_electronics_express_publishing.pdf
    • http://gezixus.myartsonline.com/majuvapabo.pdf
    • http://winimoviwimi.myartsonline.com/celastrus_paniculatus_chemical_constituents.pdf
    • https://8569cc17-8b2a-4187-ace0-95b0550b99f0.filesusr.com/ugd/d6eede_25971cbd1dab4f5d964b85a6d68403cb.pdf?index=true
    • http://dilexaluv.epizy.com/pijefipepunaxom.pdf
    • https://s3.amazonaws.com/sefiwegegagu/90032170217.pdf
    • https://4b5f4e46-8b81-4257-bf39-61fc08ba57b0.filesusr.com/ugd/7ea8bb_e322bac1ce474423bb05faf533835362.pdf?index=true
    • http://kipejefanowisu.atwebpages.com/59185369286.pdf
    • http://bibebebimil.epizy.com/international_journal_of_electronics_and_communication_impact_factor.pdf
    • http://roxigivakupumun.epizy.com/85085524153.pdf
    • https://s3.amazonaws.com/lixisariwulo/chronicles_of_darkness_dice_roller.pdf
    • https://eeeff038-21f9-42a6-bde0-cd945221d618.filesusr.com/ugd/9dc459_bfb28131d3e3448b921a5eb184c15c35.pdf?index=true
    • 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://scripts.sil.org/OFL
    • 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_off00014a91.bin
4b55710ff377a58a0bf8262fe6a628c033ff00241b6ce638d2e0db66d95c0931
pdf-font-stream PDF embedded font (sfnt) at offset 0x14A91 5524 bytes
font_01_sfnt_off00015d6a.bin
cae6c097ca882b4a292242e95c48f7bcd4df5a5e999db1f45d6c465e1117cb2f
pdf-font-stream PDF embedded font (sfnt) at offset 0x15D6A 11708 bytes
font_02_sfnt_off000184f9.bin
fb7b45e24c28c4473d0ca1c6410c593992d9a809009f9c41b5ae32c9142507dd
pdf-font-stream PDF embedded font (sfnt) at offset 0x184F9 16120 bytes