Malicious PDF — malware analysis report

Static analysis result for SHA-256 b57669c5a8abe2c5…

MALICIOUS

PDF

71.9 KB Created: 2021-02-26 20:51:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cc816b82ff13650bc154720baebfb9a9 SHA-1: 70e060844b62c7f97a81c6e6d5ff6375a6386255 SHA-256: b57669c5a8abe2c5f591cd3f89bc762e0a4460864cdaf114d904544cba4f2014
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing attempt. It contains numerous embedded URLs, with one prominent URL suggesting a lure related to textbook solutions. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the malicious intent by identifying a link farm on disposable hosting, likely used to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://crophysi.ru/123?utm_term=mechanics+of+materials+beer+5th+edition+solutions
    • https://cdn-cms.f-static.net/uploads/4381318/normal_5fe8129e7c2d9.pdf
    • https://cdn-cms.f-static.net/uploads/4388407/normal_5fd64ef946f54.pdf
    • https://cdn.sqhk.co/zusegekum/mhgheyF/adventure_capitalist_tips_ps4.pdf
    • https://cdn.sqhk.co/nufesewepi/gfejhhd/pinballz_austin_vr.pdf
    • http://tezuveripoxub.mypressonline.com/a_wifes_story_summary_by_bharati_mukherjee.pdf
    • https://vekerarefatada.weebly.com/uploads/1/3/4/8/134868636/3507600.pdf
    • https://netafipagugid.weebly.com/uploads/1/3/0/8/130814009/ea5870ee8.pdf
    • https://tadonajates.weebly.com/uploads/1/3/4/3/134319020/rowomofamisoze.pdf
    • https://cdn.sqhk.co/judixixelof/ieie1gi/tiger_shroff_song_2020_download.pdf
    • https://static.s123-cdn-static.com/uploads/4378157/normal_5fe5b1c9b0c4f.pdf
    • https://cdn.sqhk.co/zebenane/hcQz7np/tuzal.pdf
    • http://ludirobus.getenjoyment.net/can_you_breed_dapple_dachshunds.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://kosezofejesuxef.atwebpages.com/70579324531.pdf
    • http://xoxozuzupa.rf.gd/34262914009.pdf
    • http://bitines.myartsonline.com/77921163280.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_off0000da28.bin
2158f49c86e38f4f36d5842e25c6f3a23f5515bd844ead240668fce3962feee0
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA28 5528 bytes
font_01_sfnt_off0000ecd7.bin
4935575cdccf41aaf74a3c480eac1d5d3d2945deef59d7b90f86b45c58b72660
pdf-font-stream PDF embedded font (sfnt) at offset 0xECD7 11128 bytes