Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8d9e8f225f3ab3…

MALICIOUS

PDF

72.6 KB Created: 2021-09-17 06:01:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f6cdcf580cb9e82a52f72164dc734b8b SHA-1: f270a62b8cda0b1a8608eae7e8c325f3141654dc SHA-256: 5c8d9e8f225f3ab3a668af45761878ac7f0f45b44d1b6fd7d23d7dc87d44fe2c
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various domains, suggesting it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifies this behavior, indicating a tactic to obscure the ultimate destination or distribute malicious content across multiple sites. No scripts were extracted, but the structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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.
  • 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 http://www.fuchingrading.com/upload/file/jemejugetetevivufadudubek.pdf In PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/58018637267.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/58353756393.pdfIn PDF document text
    • http://hasanmasat.com/ckfinder/userfiles/files/damowudejivulajasalo.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/xafepimedejumavolujafu.pdfIn PDF document text
    • http://cuanhuaabshanquoc.vn/files/24963008098.pdfIn PDF document text
    • http://foodchemsino.com/d/files/kobuwuzasenuwajimaruwa.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/kitivix.pdfIn PDF document text
    • http://mc-opony.pl/files/file/60591580873.pdfIn PDF document text
    • http://bckbytow.naszbip.pl/img/upload/files/rujigenevugomanobub.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/xomiverukadagewed.pdfIn PDF document text
    • https://lesura.net/userfiles/file/44590529677.pdfIn PDF document text
    • http://antonioruizabogados.es/userfiles/file/98812676597.pdfIn PDF document text
    • http://actybrain-consult.com/Upload/files/30032562611.pdfIn PDF document text
    • https://bonvoyageindia.in/ckfinder/userfiles/files/wenowavadubasidoga.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/3681cf40c5035c09aa7508879e1ed561/tuvomopolovimetifus.pdfIn PDF document text
    • http://gonvvama.net/filespath/files/20210906135745.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/lutusudideju.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/fipixigepi.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202109120801273303.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/nedodawedokor.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109011525082887.pdfIn PDF document text
    • http://pactolous.hu/upload/file/82406429262.pdfIn PDF document text
    • https://carrieres-pierre.com/userfiles/file/kipatitagu.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/50170560613.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=conical+flask+scientific+drawingPDF link annotation
    • 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://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_off0000b882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB882 10860 bytes
SHA-256: b0484b61e3c658451384436aae8fb3588202a9cbe0222ec26409f1903f2f679d
font_01_sfnt_off0000d1a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e9b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B2 16788 bytes
SHA-256: 7a2de24241874b0025d2a875c25ac6e07b534105627be83c799bbd4ad886f895