Malicious PDF — malware analysis report

Static analysis result for SHA-256 cc1b7d0c5135e4e8…

MALICIOUS

PDF

77.3 KB Created: 2021-05-23 19:28:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c7c914f8d0dec4977642f41d67381777 SHA-1: 0a9b4a639d6932218183299fa68457b30f047735 SHA-256: cc1b7d0c5135e4e8ead9798fd5b545c290fe4510ab1fa5c7e054ab1a7d29f217
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including ClamAV and an ML classifier. It contains a large number of external links, with the primary URL being `https://golowaki.ru/strik?utm_term=crazy+frog+ringtone+free`. The PDF_SEO_LINK_FARM heuristic indicates a mass of external links, suggesting a link farm or phishing attempt. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://golowaki.ru/strik?utm_term=crazy+frog+ringtone+free
    • https://wojuguzibuliru.weebly.com/uploads/1/3/4/8/134896427/virelegevazanep-rukorider-ligapunoxekozi-tozurotib.pdf
    • https://tugufotekaluxaz.weebly.com/uploads/1/3/4/8/134883762/pokidak_ginuwoke.pdf
    • https://rilolani.weebly.com/uploads/1/3/4/4/134459611/nojoridabul-mubozasex-xexigewar.pdf
    • https://baseparefawufif.weebly.com/uploads/1/3/1/4/131453046/ce72b5ef33ea.pdf
    • https://jigaposu.weebly.com/uploads/1/3/5/3/135397088/3c96dc77c24d.pdf
    • https://vagofavom.weebly.com/uploads/1/3/4/4/134486407/givadelijobok-putazadebusafin-digabifes.pdf
    • https://romovemesokawaj.weebly.com/uploads/1/3/4/4/134479736/c6d9206ee564df.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/bc5d0b67-a783-4348-a998-4afc9da52e10/28920478969.pdf
    • https://s3.amazonaws.com/napisakaluja/32202449759.pdf
    • https://uploads.strikinglycdn.com/files/5618e7af-ebf7-48a4-92ba-38d424af8770/back_to_eden_documentary_netflix.pdf
    • https://s3.amazonaws.com/vebogotexaf/reallusion_character_creator_3.pdf
    • https://uploads.strikinglycdn.com/files/73ba36f9-1bf9-4200-9a5f-791547329903/rubelaxa.pdf
    • https://s3.amazonaws.com/zupenafud/75868262335.pdf
    • https://uploads.strikinglycdn.com/files/4eb9a200-d91a-43af-9147-386b5c4534ce/mvc_interview_questions_and_answers_for_experienced.pdf
    • https://uploads.strikinglycdn.com/files/b1688877-7423-40fa-8bb4-a8c1e880bc6b/bronica_etrs_645_review.pdf
    • https://uploads.strikinglycdn.com/files/481d74f7-d772-423c-93a0-16f4c3a9de8f/tipos_de_comunicacin_oral_debate.pdf
    • https://s3.amazonaws.com/lebejos/dfm_foods_research_report.pdf
    • https://uploads.strikinglycdn.com/files/ca23ee59-e2ed-48a7-a505-123feb33b3de/xovosusaxemibarugedopi.pdf
    • https://s3.amazonaws.com/tarizirefevifab/binary_number_conversion_table.pdf
    • https://uploads.strikinglycdn.com/files/b0ba7446-464e-44cd-b597-220fcd2ecc63/mavozixozi.pdf
    • 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f43d.bin
cdf6b615c81428232e1681ec89d993ce8400ff481ff8b1a0cc5982441c853853
pdf-font-stream PDF embedded font (sfnt) at offset 0xF43D 4780 bytes
font_01_sfnt_off000104a6.bin
c05efde91735adeaa0ba2d242c4cc7400cdba15e3c7596340a6e012f44cb7341
pdf-font-stream PDF embedded font (sfnt) at offset 0x104A6 10472 bytes