Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c00c2f567de33d9…

MALICIOUS

PDF

64.1 KB Created: 2021-02-26 14:12:23 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fce085b47efbb1feae03d3668708a30e SHA-1: 8d26377c0c3146db1bc8c3e2d74b3bbd6e9d1909 SHA-256: 3c00c2f567de33d96884d6cacb99307803e0d1174859ee4249482031afa7fe25
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, a common tactic for link farms and phishing. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of links, and the 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' firings strongly suggest malicious intent. The document body, though heavily obfuscated, contains text related to 'Wooldridge econometrics answer key', which is likely a lure to direct users to malicious URLs like 'https://nipisod.ru/strik?utm_term=wooldridge+econometrics+answer+key'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

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://nipisod.ru/strik?utm_term=wooldridge+econometrics+answer+key
    • https://cdn.sqhk.co/tomubozes/jawagcp/93953444783.pdf
    • https://cdn.sqhk.co/xederebat/jcjbAja/90939399274.pdf
    • https://xufidevudog.weebly.com/uploads/1/3/4/3/134389214/gojifolodas.pdf
    • http://xoroketogejuxe.mywebcommunity.org/8710868942.pdf
    • https://wutejaguruloz.weebly.com/uploads/1/3/1/8/131871665/somefufiv.pdf
    • http://rasudilikid.mywebcommunity.org/how_to_mix_food_grade_hydrogen_peroxide.pdf
    • https://cdn.sqhk.co/vidikusupegu/ijhejjj/xunozezaxuvad.pdf
    • https://popuverixi.weebly.com/uploads/1/3/1/4/131438274/linomepumi-xefunuf-kitagufa-kerovadak.pdf
    • https://cdn.sqhk.co/keridola/6gjihjf/video_bingo_mentone.pdf
    • https://cdn.sqhk.co/zifiguwosu/hjjahhk/569349614.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/bejenosugede/empire_total_war_darthmod_strategy_guide.pdf
    • https://s3.amazonaws.com/paxuvagal/anderson_paak_bubblin_free.pdf
    • http://tizidirek.rf.gd/1508511182.pdf
    • http://pijopatamotawu.epizy.com/fudunajimakuno.pdf
    • http://kopolug.myartsonline.com/72371161754.pdf
    • http://lejemerane.epizy.com/33865421209.pdf
    • https://s3.amazonaws.com/vaxebisapesi/94706302972.pdf
    • http://wulibazosuxib.onlinewebshop.net/wogogof.pdf
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5df.bin
28d1e2c3aad3959b9db98264c294c27f2624edd6d6485aeb7371b3e11ade134d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC5DF 5528 bytes
font_01_sfnt_off0000d8b2.bin
d6f7aecf50ce1b3f9ef363b460376d75850df5ac598b5a15f987062b04a6876b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B2 10452 bytes