Malicious PDF — malware analysis report

Static analysis result for SHA-256 8adcd0a5e42392a6…

MALICIOUS

PDF

57.4 KB Created: 2020-07-29 16:53:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f0eab0cfaf9d7304ac97d177ea4f6ca6 SHA-1: 2395c92bda9459bbc7fea65c6f41e1e49af32a41 SHA-256: 8adcd0a5e42392a65c01368379104abf049c2d2f0d67e9022dbe7458a78e49a4
152 Risk Score

Malware Insights

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

The PDF was flagged as malicious due to a critical heuristic identifying a link to a known malicious redirector. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf. The presence of numerous external links, many pointing to Shopify domains, indicates a link farm or redirection strategy. The primary malicious IOC is the redirector URL, which is likely used to funnel victims to a phishing or malware distribution site.

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=beczka+amontillado+pdf
    • http://files.corkgp.com/uploads/1/3/1/4/131438137/jesasanewupewekikax.pdf
    • http://files.numerat.com/uploads/1/3/1/3/131381679/b8d6fa4e525e.pdf
    • http://files.meatfreemondayfood.com/uploads/1/3/0/7/130740242/belujanusekovu.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/40369191557.pdf
    • https://cdn.shopify.com/s/files/1/0430/4538/8437/files/sokedog.pdf
    • https://cdn.shopify.com/s/files/1/0428/8331/7926/files/tuwikudituxim.pdf
    • https://cdn.shopify.com/s/files/1/0433/5638/9528/files/40659167670.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/zekimopesafirizaxos.pdf
    • https://cdn.shopify.com/s/files/1/0436/5231/7342/files/38570975641.pdf
    • https://cdn.shopify.com/s/files/1/0438/1766/4674/files/49033367949.pdf
    • https://cdn.shopify.com/s/files/1/0440/9756/8920/files/begozewulu.pdf
    • https://cdn.shopify.com/s/files/1/0432/2508/8168/files/42255341507.pdf
    • https://cdn.shopify.com/s/files/1/0431/6397/5835/files/43814057619.pdf
    • https://cdn.shopify.com/s/files/1/0432/8026/9477/files/42201663957.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/1028728638.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/xubeke.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_off0000a46a.bin
2b72fcb583a096178980e201e94d8fd1d2e0c25d4145f7357f0d491fe2c9b0f0
pdf-font-stream PDF embedded font (sfnt) at offset 0xA46A 4976 bytes
font_01_sfnt_off0000b548.bin
2fff76d407372abb67f881c92a9c87682aeef2da605ac572b4b1425e91419278
pdf-font-stream PDF embedded font (sfnt) at offset 0xB548 10280 bytes