Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b87baac7b0a9559…

MALICIOUS

PDF

94.8 KB Created: 2021-03-15 03:44:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 395dc577f3e41b8b66efebfe0364c3e8 SHA-1: 3529ec5333cfc6114ce480c092a2645973abeaf2 SHA-256: 4b87baac7b0a95591c8bfe34584823ecc40f13af6e8f9b6e7380fb1c6d7164ad
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to redirectors and SEO farms, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_UTM_REDIRECTOR_LINK' strongly suggest this. The ML classifier and ClamAV detection further confirm its malicious nature. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure point towards a malicious document designed to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://mezovuduw.ru/123?utm_term=fax+cover+sheet+sample+pdf PDF link annotation
    • https://cdn.sqhk.co/xevowuto/idhdjcl/popumevufidisoge.pdfIn PDF document text
    • http://like-store.site/winevezikimilavimowug8utg.pdfIn PDF document text
    • https://cdn.sqhk.co/nomitusibop/eheigl3/top_up_ff_duniagames_murah.pdfIn PDF document text
    • http://passive-income.ru/chemistry_unit_4_test_b_answersjcuih.pdfIn PDF document text
    • http://espaceabonnes.com/83537909810n9jkx.pdfIn PDF document text
    • http://smartbright.club/63883195199wuu21.pdfIn PDF document text
    • https://cdn.sqhk.co/gojogefe/dgjjcjc/26489905787.pdfIn PDF document text
    • https://cdn.sqhk.co/jefulajidi/jcNgGY9/john_lewis_television_buying_guide.pdfIn PDF document text
    • https://cdn.sqhk.co/wedegetuso/fifyT5X/alone_images_sad.pdfIn PDF document text
    • http://bettermoneytips.com/chapati_roti_video57jvq.pdfIn PDF document text
    • https://cdn.sqhk.co/legusovej/28sCicK/phonetics_and_phonology_notes.pdfIn PDF document text
    • https://cdn.sqhk.co/wifuponi/qenPtif/janudegamo.pdfIn PDF document text
    • https://cdn.sqhk.co/lowixadoges/gcgduK8/97187348292.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/badodemebo/12651120276.pdfIn PDF document text
    • https://s3.amazonaws.com/baritexovopa/combined_gas_law_practice_problems_with_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/nabifovu/sinaw.pdfIn PDF document text
    • https://s3.amazonaws.com/rujabepifar/cash_flow_statement_format_in_direct_method.pdfIn PDF document text
    • https://s3.amazonaws.com/kavugusepe/86222226835.pdfIn PDF document text
    • https://0f939073-77d1-4307-aaa8-42539c8515e3.filesusr.com/ugd/85c9df_c1c88f89edf84954a1cfab8902592143.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zepifudoxapo/facebook_messenger_last_update_apk.pdfIn PDF document text
    • https://s3.amazonaws.com/nigimul/gifujolobaxirugagasar.pdfIn PDF document text
    • https://810dce77-56ab-4324-823a-3549757f4eab.filesusr.com/ugd/1fad07_16c2563ab3194b5b9e20d02fec22978d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nijosinizo/salesforce_apex_interview_questions.pdfIn PDF document text
    • https://s3.amazonaws.com/mogedozara/wabapanoxur.pdfIn PDF document text
    • https://s3.amazonaws.com/sefipa/snappy_answer_crossword_puzzle_clue.pdfIn PDF document text
    • https://e9593579-f51f-4dc6-af55-2543ab512b45.filesusr.com/ugd/37952c_abbdff2b4e2f4f01ae9326504c81f458.pdf?index=trueIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13400 5480 bytes
SHA-256: 898dc1f1ea36a8cd65cef0dd25bc5aa31099cb79627f12d97bb83977b765d31f
font_01_sfnt_off00014685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14685 11636 bytes
SHA-256: b52c5bfff4562c80134659abf1727ba8335fafa7b4806392b79f92eff4a7a110