Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d1cdbd355dcc02…

MALICIOUS

PDF

44.2 KB Created: 2020-07-28 21:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c54a530a9c7a1909a171bb2fd89ebd8c SHA-1: 7aa21f5d8717d63d9300733b309d1c13d237eded SHA-256: 91d1cdbd355dcc02c9d41f00abdf4567f29a9f2f6a00d70f1ecaa389b111bcb5
152 Risk Score

Malware Insights

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

The PDF document was flagged by multiple critical heuristics, including PDF_MALICIOUS_REDIRECTOR_LINK and PDF_SEO_LINK_FARM, indicating it is designed to host a large number of external links. The ML classifier also strongly indicated maliciousness. The primary malicious IOC is the redirector URL, which likely leads to further malicious content. The document body is heavily obfuscated and unreadable, but the heuristics and URLs are sufficient to determine the attack pattern.

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.cc/pify?keyword=gmp+standards+performance+and+attendance+policy
    • http://files.crochetnecklacesbyconna.com/uploads/1/3/0/7/130740217/jowuriropajonif.pdf
    • http://files.fnaq.org/uploads/1/3/0/9/130969944/nivubuluro.pdf
    • http://files.paratutor.com/uploads/1/3/1/3/131383651/zowugaleminuvak.pdf
    • http://files.paratutor.com/u
    • https://cdn.shopify.com/s/files/1/0428/0002/1667/files/giwutolifof.pdf
    • https://cdn.shopify.com/s/files/1/0438/5603/5990/files/dolubidag.pdf
    • https://cdn.shopify.com/s/files/1/0429/5180/3033/files/4802296468.pdf
    • https://cdn.shopify.com/s/files/1/0434/3716/2657/files/jaxugoxufeparifudoku.pdf
    • https://cdn.shopify.com/s/files/1/0431/9903/7595/files/32298988243.pdf
    • https://cdn.shopify.com/s/files/1/0431/7102/0954/files/57953233672.pdf
    • https://cdn.shopify.com/s/files/1/0430/2651/4077/files/42443276175.pdf
    • https://cdn.shopify.com/s/files/1/0428/7237/3414/files/504733644.pdf
    • https://cdn.shopify.com/s/files/1/0433/9915/1768/files/63518385745.pdf
    • https://cdn.shopify.com/s/files/1/0435/3366/4420/files/giwukowixobi.pdf
    • https://cdn.shopify.com/s/files/1/0431/4683/8167/files/jexadisusuz.pdf
    • https://cdn.shopify.com/s/files/1/0433/1828/0357/files/nerujizukivexuw.pdf
    • https://cdn.shopify.com/s/files/1/0432/0156/0737/files/xunolugunevepepowimuzumu.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_off00006ff1.bin
0ecb443b2894bc697cac0d08ca563a2a084a51db2060e7abc609ab87d947a686
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FF1 5224 bytes
font_01_sfnt_off000081a3.bin
8eef85eb312e56f8d22247c574baf0ba31831551b64c14dc0c2fa727e2353ee3
pdf-font-stream PDF embedded font (sfnt) at offset 0x81A3 9904 bytes