Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0ac52963b0af917…

MALICIOUS

PDF

41.8 KB Created: 2020-08-03 18:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c56c5c91ade4e53d177e8661bd71afb8 SHA-1: d29ebdc75ea992752862d9df4bf66078d025bff0 SHA-256: a0ac52963b0af917ff89c2d03bf41a2c17abd1e7983689cf6a4048fe7c04c2b8
154 Risk Score

Malware Insights

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

The PDF file was identified as malicious due to its inclusion of a mass external PDF link farm and a direct link to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'linear approximation problems and solutions pdf' and the malicious URL. The primary malicious IOC is the redirector URL, which likely serves as a gateway to further malicious content. No scripts were extracted, and the PDF structure itself is the vector for the attack.

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.ru/pify?keyword=linear+approximation+problems+and+solutions+pdf
    • http://files.mobileonegaming.com/uploads/1/3/2/3/132303082/33260338a.pdf
    • http://files.lynbrookels.com/uploads/1/3/1/8/131856539/vusujafesitod.pdf
    • http://gefixun.makeupbystar.com/uploads/1/3/0/8/130873791/d5969879090413c.pdf
    • https://cdn.shopify.com/s/files/1/0432/2423/6199/files/levefozum.pdf
    • https://cdn.shopify.com/s/files/1/0436/4579/6512/files/13788584015.pdf
    • https://cdn.shopify.com/s/files/1/0438/0655/6322/files/spying_on_sister.pdf
    • https://cdn.shopify.com/s/files/1/0429/1582/3772/files/39010053057.pdf
    • https://cdn.shopify.com/s/files/1/0428/9059/2422/files/2013_kia_soul_owners_manual.pdf
    • https://cdn.shopify.com/s/files/1/0441/3577/6408/files/togekuwujadekawaz.pdf
    • https://cdn.shopify.com/s/files/1/0432/5592/2852/files/9206757133.pdf
    • https://cdn.shopify.com/s/files/1/0438/7491/0376/files/pigozulafapin.pdf
    • https://cdn.shopify.com/s/files/1/0428/0087/3631/files/35933580850.pdf
    • https://cdn.shopify.com/s/files/1/0440/6145/8582/files/37596320775.pdf
    • https://cdn.shopify.com/s/files/1/0430/3015/1330/files/93661829820.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_off00005c8f.bin
8f53810058848acfb49364ad03985b3ade950ed5ac0ce4e10b59badca9e4b07f
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C8F 5336 bytes
font_01_sfnt_off00006e9f.bin
aae98cff50b124124ade5276151cd533753fa65bb1b2ed0c18908fb755c8e0e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E9F 13812 bytes