Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d9c9731bb1a5e5b…

MALICIOUS

PDF

71.3 KB Created: 2021-01-15 07:18:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 41db9bced43da3f9b20a6097ff529f01 SHA-1: 7a476a2102e45beafd9fda624356d75b9b07d3ff SHA-256: 7d9c9731bb1a5e5be33daeb37d6380cf322b0dfd99f9be983f07d418f1b1910b
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as a phishing trojan. The document contains numerous external links, including a link farm, and the embedded content suggests a lure related to 'chapter 13 cardiovascular system worksheet answers'. The presence of external URIs and the overall structure indicate an attempt to redirect users to potentially malicious sites for further exploitation or phishing.

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://traffking.ru/123?utm_term=chapter+13+cardiovascular+system+worksheet+answers
    • https://fumirufax.weebly.com/uploads/1/3/1/8/131856188/3842307.pdf
    • https://site-1176250.mozfiles.com/files/1176250/36175958597.pdf
    • https://cdn-cms.f-static.net/uploads/4366018/normal_5f88ce331f1bb.pdf
    • https://cdn-cms.f-static.net/uploads/4381978/normal_5f9a6cda6b216.pdf
    • https://mubuvume.weebly.com/uploads/1/3/4/8/134885019/giwepeni.pdf
    • https://site-1172508.mozfiles.com/files/1172508/blood_pressure_monitor_wrist_watch.pdf
    • https://site-1204816.mozfiles.com/files/1204816/magic_tiles_piano_and_vocal_mod_apk.pdf
    • https://static.s123-cdn-static.com/uploads/4449629/normal_5ffd62c0e3f85.pdf
    • https://cdn-cms.f-static.net/uploads/4369796/normal_5fa41c0fa98fc.pdf
    • https://madigapelodawip.weebly.com/uploads/1/3/4/8/134846312/jekebalubabaxulu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/gelawiweza/27659656270.pdf
    • https://s3.amazonaws.com/gogunabones/5774222380.pdf
    • https://s3.amazonaws.com/mefovu/dubenefama.pdf
    • https://s3.amazonaws.com/xaliwalufoguni/email_format_for_request_letter.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_off0000d822.bin
58633f1301305b8c1dd8b140a0c0c940ad70a8f702d36567bbdfab6e3b8e3eb7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD822 5752 bytes
font_01_sfnt_off0000eba8.bin
6c483aa330f7f1b72d0368fc679ece1c9fb51c29df4417fb0c94b5838d33b1bd
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA8 10736 bytes