Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5e5394ac0492d2b…

MALICIOUS

PDF

51.2 KB Created: 2020-09-01 10:18:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 32b0fd26872cbe36a4f5ed8fddbe7134 SHA-1: 4b9f52775cc9480522b281c79bdd598459f97d9c SHA-256: c5e5394ac0492d2b8632142cb5c4a95cf54be09332c92e1253f07d27dee50f9b
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm hosted on cdn.shopify.com. One critical heuristic identified a link to a known malicious redirector at https://ttraff.ru/wix?keyword=airserver+full+free++pc. The document body, though heavily obfuscated, contains references to the search term 'airserver full free pc', suggesting a lure for pirated software. The ML classifier also strongly indicated maliciousness.

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/wix?keyword=airserver+full+free++pc
    • https://static.usrfiles.com/ugd/f515ca_8810a9a8e1594e49bedeb86e8c8a8f13.pdf
    • https://static.usrfiles.com/ugd/03ae60_f991ae44de604eb2b0eb245ac4754e31.pdf
    • https://static.usrfiles.com/ugd/9ff9b8_835926d3f93a40628035b527b412b540.pdf
    • https://static.usrfiles.com/ugd/ad2ade_57a8af5614bb4cb2919f30c7d1adb352.pdf
    • https://static.usrfiles.com/ugd/69b86f_0b8c9dec7e394f0b8530d678ddd7c5a4.pdf
    • https://cdn.shopify.com/s/files/1/0429/8765/1235/files/womoj.pdf
    • https://cdn.shopify.com/s/files/1/0435/0767/9397/files/loraine_boettner_catolicismo_romano.pdf
    • https://cdn.shopify.com/s/files/1/0427/8370/3206/files/21937885364.pdf
    • https://cdn.shopify.com/s/files/1/0433/4390/4927/files/vanuzitatepanawomike.pdf
    • https://cdn.shopify.com/s/files/1/0439/0017/4504/files/udp_tracker_istole_it_80_announce.pdf
    • https://cdn.shopify.com/s/files/1/0432/0873/6927/files/dezelobatanoxodute.pdf
    • https://cdn.shopify.com/s/files/1/0437/6703/8106/files/22516424432.pdf
    • https://cdn.shopify.com/s/files/1/0430/9866/9220/files/pofujenawetovati.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_off0000830c.bin
09aad22ac50c34177dca6d5b940fcb531060d772ae8182790741ce84ac94f884
pdf-font-stream PDF embedded font (sfnt) at offset 0x830C 4848 bytes
font_01_sfnt_off000093a8.bin
251e8c9bac8973b80300ebb8748291f1f502573b33a4d10b50c71dc9bb58fc79
pdf-font-stream PDF embedded font (sfnt) at offset 0x93A8 14196 bytes