Malicious PDF — malware analysis report

Static analysis result for SHA-256 98b12cea77d502d1…

MALICIOUS

PDF

40.2 KB Created: 2020-08-07 16:21:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cfaab0bcf982561badaad889480dfc4f SHA-1: 1efd3de7813a9798fa81db656bde848ebd7340fc SHA-256: 98b12cea77d502d1c99a9438e0ba4941671ad693710a3dee1fdaedca0ba5f66b
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains embedded links that redirect to malicious infrastructure, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text suggesting a lure related to 'Gmat mock test pdf'. The presence of a link farm and the ML classifier flagging the PDF further support its malicious nature. The primary IOC is the redirector URL which is designed to lead users to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.com/pify?keyword=gmat+mock+test+pdf
    • http://mojoti.takaikari.com/uploads/1/3/1/8/131871390/01285.pdf
    • http://files.stanleyjusticeproductions.com/uploads/1/3/1/3/131397971/58071.pdf
    • http://kawozij.voiceofhoperct.org/uploads/1/3/0/7/130739777/758c8e499985a.pdf
    • https://cdn.shopify.com/s/files/1/0428/5782/4415/files/2504881117.pdf
    • https://cdn.shopify.com/s/files/1/0431/6374/6465/files/jobamulubopagufirete.pdf
    • https://cdn.shopify.com/s/files/1/0433/3050/2806/files/zipumam.pdf
    • https://cdn.shopify.com/s/files/1/0431/0781/1495/files/firefox_for_windows_xp.pdf
    • https://cdn.shopify.com/s/files/1/0433/8850/2174/files/11647433133.pdf
    • https://cdn.shopify.com/s/files/1/0429/9482/7415/files/dugasibufazolewamumapez.pdf
    • https://cdn.shopify.com/s/files/1/0432/7414/1864/files/mortal_kombat_x.pdf
    • https://cdn.shopify.com/s/files/1/0434/2746/3324/files/gidoxajalowoselatakomege.pdf
    • https://cdn.shopify.com/s/files/1/0435/5964/9429/files/tanugivoxalulepelimu.pdf
    • https://cdn.shopify.com/s/files/1/0429/0193/0143/files/88470461402.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005d7e.bin
a0e51b957b3495c6a777cd7c349fa71fbe990290beb22dc73ed01f61b3f38f99
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D7E 5268 bytes
font_01_sfnt_off00006f65.bin
568ce14fb7edd08db7283b4074d60a5669f08888d98a4858ea79e3934747fc03
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F65 10928 bytes