Malicious PDF — malware analysis report

Static analysis result for SHA-256 a78d0eb8c99b5a35…

MALICIOUS

PDF

79.2 KB Created: 2021-06-02 13:02:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0015d152b0ac7ec5f00c79a187ef2f88 SHA-1: f6e86f376e8f843e7a89a4ed3ad867a50903d316 SHA-256: a78d0eb8c99b5a35a909f144d6842207ce71e09d1671f70953f26f44ab20d09d
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, as indicated by the PDF_SEO_LINK_FARM heuristic. One of these links, https://baarspo.ru/123?utm_term=spikes+format+breaking+bad+news, is directly embedded. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution through these links. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

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://baarspo.ru/123?utm_term=spikes+format+breaking+bad+news
    • https://wemavepudobug.weebly.com/uploads/1/3/4/1/134108610/6326189.pdf
    • https://cdn-cms.f-static.net/uploads/4455375/normal_602831ee7421a.pdf
    • https://cdn-cms.f-static.net/uploads/4475729/normal_6044a083c2bf7.pdf
    • https://cdn-cms.f-static.net/uploads/4419437/normal_5fe6c58f6f3a8.pdf
    • https://static.s123-cdn-static.com/uploads/4498366/normal_5fc9da3d36710.pdf
    • https://static.s123-cdn-static.com/uploads/4366676/normal_5ffd46d695072.pdf
    • https://cdn-cms.f-static.net/uploads/4369640/normal_601ccadc1d55a.pdf
    • https://cdn-cms.f-static.net/uploads/4375690/normal_6069f38061566.pdf
    • https://wowavimisaken.weebly.com/uploads/1/3/0/8/130814021/9978300.pdf
    • https://cdn-cms.f-static.net/uploads/4392660/normal_6063ee4081c32.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/7f9edac3-2b4e-4f68-996f-e10ec8fe588b/zimunedumugefaf.pdf
    • http://xesimisejek.pbworks.com/w/file/fetch/144503433/missing_angle_puzzle_worksheet_answers.pdf
    • https://uploads.strikinglycdn.com/files/fd700069-a9b5-4e5f-8ec5-787e7ab98d9d/64766932032.pdf
    • https://uploads.strikinglycdn.com/files/481b12c5-b334-4130-9537-4e74c587359b/52600634254.pdf
    • https://uploads.strikinglycdn.com/files/403e4e92-94da-4377-b949-e016978dc7bf/vanguard_total_bond_market_index_fund_price_history.pdf
    • https://uploads.strikinglycdn.com/files/d852f1e1-63ac-4f42-8874-ab1827e244be/9933564816.pdf
    • https://uploads.strikinglycdn.com/files/c79be4c1-bbfe-4d9b-9f8b-53cbd90178d9/felate.pdf
    • https://uploads.strikinglycdn.com/files/cb9d207d-f3ca-42aa-8b7b-f14a74ec2706/63369059841.pdf
    • http://kalunagepigi.pbworks.com/w/file/fetch/144425433/hotel_housekeeping_checklist_form.pdf
    • http://sisagexal.pbworks.com/w/file/fetch/144504012/briggs_and_stratton_450e_125cc_oil_capacity.pdf
    • https://uploads.strikinglycdn.com/files/1e032297-3759-4ed2-b927-4b1a94e5734a/what_korean_language_does_bts_speak.pdf
    • http://lakebimutep.pbworks.com/w/file/fetch/144418371/difference_between_direct_method_and_grammar_translation_method.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_off0000f824.bin
c9833f8611eb064367e8e3001839c45b9dd25d41d4df58f0255295f913cde516
pdf-font-stream PDF embedded font (sfnt) at offset 0xF824 5728 bytes
font_01_sfnt_off00010b9d.bin
752fdd2a3f06af767d5cbc0372979b148eabaf81a29e56044595d06a8cc6efb7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9D 10560 bytes